Important Kunena External Images disappear!

This is my configuration

Database collation check: The collation of your table fields are correct

Legacy mode: Disabled | Joomla! SEF: Enabled | Joomla! SEF rewrite: Enabled | FTP layer: Disabled |

This message contains confidential information

htaccess: Exists | PHP environment: Max execution time: 30 seconds | Max execution memory: 170M | Max file upload: 12M

Kunena menu details:

Warning: Spoiler!

ID	Name	Menutype	Link	Path
94	Forum	mainmenu	Itemid=245	kunenaforum
200	Valutazioni	forummenu	view=category&catid=25	valutazioni
202	Il Forum di Toysforce	mod_menu	view=category&layout=list&catid=0	il-forum-di-giocattoli-vecchi-fb
245	Il Forum di Toysforce	kunenamenu	view=home&defaultmenu=245	forum
156	test	menuutente	view=home	test
180	Presentazione Nuovi Utenti	forummenu	view=category&catid=2	presentazioni
181	Facebook Area Utenti	forummenu	view=category&catid=19	facebook-area-utenti
182	Area Tecnica/Comunicazioni Di Servizio	forummenu	view=category&catid=15	area-tecnicacomunicazioni-di-servizio
183	Discussioni / Suggerimenti Sul Forum	forummenu	view=category&catid=3	discussioni-suggerimenti-sul-forum
184	Action Figures	forummenu	view=category&catid=17	action-figures
185	Motu Classics	forummenu	view=category&catid=21	motu-classics
186	Robots-Vintage	forummenu	view=category&catid=4	robots-vintage
187	Robots-New Models	forummenu	view=category&catid=5	robots-new-models
188	Retrogames	forummenu	view=category&catid=6	retrogames
189	Videogiochi Nuovi	forummenu	view=category&catid=7	videogiochi-nuovi
190	45 giri, Lp, Cd Materiale Audio Video	forummenu	view=category&catid=8	45-giri-lp-cd-materiale-audio-video
191	Fumetti, Manga, Comics,Topolino ecc	forummenu	view=category&catid=20	fumetti-manga-comicstopolino-ecc
192	Sezione Girls	forummenu	view=category&catid=12	sezione-girls
193	Di Tutto Di Più	forummenu	view=category&catid=13	di-tutto-di-piu
194	Spam	forummenu	view=category&catid=14	spam
195	Secret Area	forummenu	view=category&catid=23	secret-area
196	Area Servizio Annunci	forummenu	view=category&catid=10	area-servizio-annunci
197	Area Servizio Aste	forummenu	view=category&catid=11	area-servizio-aste
198	Area Feedback Annunci	forummenu	view=category&catid=16	area-feedback-annunci
11	Il Forum	mainmenu	view=category&catid=0&layout=list	home-joomla
246	Indice delle categorie	kunenamenu	view=category&layout=list	forum/home
247	Argomenti Recenti	kunenamenu	view=topics&mode=replies	forum/recente
248	Nuovo argomento	kunenamenu	view=topic&layout=create	forum/nuovotopic
249	Senza risposta	kunenamenu	view=topics&mode=noreplies	forum/senzarisposte
250	Le mie discussioni	kunenamenu	view=topics&layout=user&mode=default	forum/mieitopics
251	Profilo del Forum	kunenamenu	view=user	forum/profilo
252	Aiuto	kunenamenu	view=misc	forum/aiuto
253	Ricerca	kunenamenu	view=search	forum/cerca

Joomla default template details : animania2 | author: | version: 1.0 | creationdate: 2012-06-07

Kunena default template details : Blue Eagle 2.0 | author: Kunena Team | version: 2.0.2 | creationdate: 2012-09-02

Kunena version detailed: Kunena 2.0.2 | 2012-09-02 [ Botschafter ]
| Kunena detailed configuration:

Warning: Spoiler!

Kunena config settings:
board_offline	0
enablerss	1
threads_per_page	20
messages_per_page	15
messages_per_page_search	15
showhistory	1
historylimit	6
shownew	1
disemoticons	0
template	blue_eagle
showannouncement	1
avataroncat	1
catimagepath	category_images/
showchildcaticon	1
rtewidth	450
rteheight	300
enableforumjump	1
reportmsg	1
username	1
askemail	0
showemail	0
showuserstats	1
showkarma	1
useredit	1
useredittime	0
useredittimegrace	600
editmarkup	1
allowsubscriptions	1
subscriptionschecked	1
allowfavorites	1
maxsubject	250
maxsig	300
regonly	0
pubwrite	0
floodprotection	0
mailmod	0
mailadmin	0
captcha	0
mailfull	1
allowavatarupload	1
allowavatargallery	1
avatarquality	65
avatarsize	2048
imageheight	1050
imagewidth	1680
imagesize	3500
filetypes	txt,rtf,pdf,zip,tar.gz,tgz,tar.bz2
filesize	120
showranking	1
rankimages	1
userlist_rows	30
userlist_online	1
userlist_avatar	1
userlist_name	1
userlist_posts	1
userlist_karma	1
userlist_email	0
userlist_usertype	0
userlist_joindate	1
userlist_lastvisitdate	1
userlist_userhits	1
latestcategory	0
showstats	1
showwhoisonline	1
showgenstats	1
showpopuserstats	1
popusercount	5
showpopsubjectstats	1
popsubjectcount	5
usernamechange	0
showspoilertag	1
showvideotag	1
showebaytag	1
trimlongurls	1
trimlongurlsfront	40
trimlongurlsback	20
autoembedyoutube	1
autoembedebay	1
ebaylanguagecode	it-it
sessiontimeout	1800
highlightcode	0
rss_type	topic
rss_timelimit	month
rss_limit	100
rss_included_categories
rss_excluded_categories
rss_specification	rss2.0
rss_allow_html	1
rss_author_format	name
rss_author_in_title	1
rss_word_count	0
rss_old_titles	1
rss_cache	900
defaultpage	recent
default_sort	asc
sef	1
sefutf8	0
showimgforguest	1
showfileforguest	1
pollnboptions	4
pollallowvoteone	1
pollenabled	1
poppollscount	5
showpoppollstats	1
polltimebtvotes	00:15:00
pollnbvotesbyuser	100
pollresultsuserslist	1
maxpersotext	50
ordering_system	mesid
post_dateformat	datetime
post_dateformat_hover	datetime
hide_ip	1
imagetypes	jpg,jpeg,gif,png
checkmimetypes	1
imagemimetypes	image/jpeg,image/jpg,image/gif,image/png
imagequality	50
thumbheight	32
thumbwidth	32
hideuserprofileinfo	put_empty
boxghostmessage	0
userdeletetmessage	0
latestcategory_in	1
topicicons	1
debug	0
catsautosubscribed	0
showbannedreason	0
version_check	1
showthankyou	1
showpopthankyoustats	1
popthankscount	5
mod_see_deleted	0
bbcode_img_secure	text
listcat_show_moderators	1
lightbox	0
show_list_time	720
show_session_type	0
show_session_starttime	0
userlist_allowed	1
userlist_count_users	1
enable_threaded_layouts	0
category_subscriptions	post
topic_subscriptions	every
pubprofile	0
thankyou_max	10
email_recipient_count	0
email_recipient_privacy	bcc
captcha_post_limit	0
keywords	0
userkeywords	0
image_upload	registered
file_upload	registered
topic_layout	flat
time_to_create_page	0
show_imgfiles_manage_profile	1
hold_newusers_posts	0
hold_guest_posts	0
attachment_limit	8
pickup_category	0
article_display	intro
send_emails	1
fallback_english	1
cache	1
cache_time	60
iptracking	1
changename	0
enablepdf	1
jmambot	0
annmodid	62
userlist_username	1
rules_infb	1
help_infb	1
onlineusers	1
plugins	Array

| Kunena integration settings:

Warning: Spoiler!

Kunena - AlphaUserPoints Disabled
Kunena - Community Builder Disabled
Kunena - Gravatar Disabled
Kunena - JomSocial Enabled: access=1 login=1 activity=1 avatar=0 profile=0 private=0 activity_points_limit=0 activity_stream_limit=0
Kunena - Joomla Enabled: access=1 login=1
Kunena - Kunena Enabled: avatar=1 profile=1
Kunena - UddeIM Enabled: private=1

| Joomla! detailed language files installed:

Warning: Spoiler!

Joomla! languages installed:
en-GB	English (United Kingdom)
it-IT	Italian - Italy

Third-party components: Jomsocial 2.6.1 | UddeIM 2.8

Third-party SEF components: None

Plugins: Content - Kunena Discuss 2.0.2 | JomSocial - My Kunena Forum Menu 2.0.2 | JomSocial - My Kunena Forum Posts 2.0.2 | JomSocial - Kunena Groups 2.0.2

Modules: Kunena Latest 2.0.2 | Kunena Search 2.0.2

I'm getting a STRANGE error on my forum.
Images uploaded and inserted show correctly. Image external with BB suffix are going to disappear after few time
This happen with images and also with a signature which have a banner inside... showing only web address but no more banner image

Here's 2 screenshot. The topic as i seen it and the links inside