Question SEF urls work only the first time, then they redirect to Index

Hi,
I installed the component twice, tried to set the menus as described in your guide, but the result is always the same: the first time all the kunena's menus work properly, but then they all redirect to Index page. Sometimes My profile menu is the only one that doesn't work.
I'm using Kunena 1.7 (with all the default settings) on Joomla 1.5.23.
Any suggestion?
Thanks in advance

Hello,

Can-i see your Kunena report configuration settings ?

Sure!

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: 32M | Max file upload: 2M

Joomla default template details : yoo_explorer | author: YOOtheme | version: 5.5.16 | creationdate: August 2011

Kunena default template details : Blue Eagle (default) | author: Kunena Team | version: 1.7.0 | creationdate: 2011-08-29

Kunena version detailled: Installed version: 1.7.0 | Build: 5135 | Version name: Tale | Kunena detailled configuration:

Warning: Spoiler!

[th]Kunena config settings:[/th]

board_title	Il forum di Respira la cultura
board_offline	0
board_ofset	0.00
offline_message	<h2>The Forum is currently offline for maintenance.</h2> <div>Check back soon!</div>
enablerss	0
enablepdf	0
threads_per_page	20
messages_per_page	6
messages_per_page_search	15
showhistory	1
historylimit	6
shownew	1
jmambot	0
disemoticons	0
template	default
showannouncement	1
avataroncat	0
catimagepath	category_images/
showchildcaticon	1
annmodid	62
rtewidth	450
rteheight	300
enableforumjump	1
reportmsg	1
username	0
askemail	0
showemail	0
showuserstats	1
showkarma	0
useredit	1
useredittime	0
useredittimegrace	600
editmarkup	1
allowsubscriptions	1
subscriptionschecked	1
allowfavorites	0
maxsubject	50
maxsig	300
regonly	0
changename	0
pubwrite	0
floodprotection	0
mailmod	0
mailadmin	0
captcha	0
mailfull	1
allowavatar	1
allowavatarupload	1
allowavatargallery	1
avatarquality	65
avatarsize	2048
allowimageupload	0
allowimageregupload	1
imageheight	800
imagewidth	800
imagesize	150
allowfileupload	0
allowfileregupload	1
filetypes	txt,rtf,pdf,zip,tar.gz,tgz,tar.bz2
filesize	120
showranking	1
rankimages	1
avatar_src	fb
fb_profile	fb
pm_component	no
userlist_rows	30
userlist_online	1
userlist_avatar	1
userlist_name	1
userlist_username	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
rules_infb	1
rules_cid	72
help_infb	1
help_cid	58
showspoilertag	1
showvideotag	1
showebaytag	1
trimlongurls	1
trimlongurlsfront	40
trimlongurlsback	20
autoembedyoutube	1
autoembedebay	1
ebaylanguagecode	en-us
fbsessiontimeout	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
fbdefaultpage	recent
default_sort	asc
alphauserpointsnumchars	0
sef	1
sefcats	0
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	ago
post_dateformat_hover	datetime
hide_ip	1
js_actstr_integration	0
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
integration_access	auto
integration_login	auto
integration_avatar	auto
integration_profile	auto
integration_private	auto
integration_activity	auto
boxghostmessage	0
userdeletetmessage	0
latestcategory_in	1
topicicons	1
onlineusers	1
debug	0
catsautosubscribed	0
showbannedreason	0
version_check	1
showthankyou	0
showpopthankyoustats	1
popthankscount	5
mod_see_deleted	0
bbcode_img_secure	text
listcat_show_moderators	1
lightbox	1
activity_limit	0
show_list_time	720
show_session_type	0
show_session_starttime	0
userlist_allowed	0
userlist_count_users	1
enable_threaded_layouts	0
category_subscriptions	post
topic_subscriptions	every
pubprofile	1
thankyou_max	10
email_recipient_count	0
email_recipient_privacy	bcc
email_visible_address
captcha_post_limit	0
recaptcha_publickey
recaptcha_privatekey
recaptcha_theme	white

Third-party components: None

Third-party SEF components: AceSEF: The file doesn't exist acesef.xml !

Plugins: System - Mootools Upgrade: Enabled | System - Mootools12: Disabled

Modules: None

Are-you using AceSEF ?

Yes, I use AceSEF but not for Kunena: I never downloaded the AceSEF plugin for Kunena...

I advise you to use only the default sef system provided by Joomla! itself, it should work better without AceSEF