Question A website, a forum, two or more templates = a lot of problems!

A website, a forum, two or more templates a lot of problems!
I am discouraged, I need to get a site with two different forums and the website uses different templates, and more than three.
A lot of problems, every time.
This time I run Kunena1.6.4 on Joomla 1.6.3 and with a very minimal template, configured as the default template AA and assigning the minimal template to menu items Kunena of (with template Andrine) research and other back to me default, then it defaults to minimal and AA to check all other menu items and it seems to work for almost two days.
Yesterday I installed also discuss the boat but is not enabled, but I do not know if it depends on it, is a clue, I have other operations with other components and menus and then call again just testing the forum I get a 500 error, but strange, is not page of the server and not the message of joomla, is a message that seems to be the template.
I tried everything but now I'm stuck, I tried to assign the template beez2 FireBoard get error but even so, I cleaned all the cache, temporary and everything else, nothing to be done on other FireBoard template there should be, is always returned Error 500!
I'm really pissed off, is it possible that Joomla should always have a big ball and chain as the lack of a for
I enclose a picture of the error, never seen this before.

I did other tests after uninstalling discuss the boat, I cleaned the cache of all extensions, all of them.
1 - I defined as the default beez2 and I get a 500 error anyway,
2 - I assigned as the default template with which I was lavorarando and everything works fine! attach image
3 - check to FireBoard 1.6.4 another template other than the default and still get error 500!
FireBoard Joomla or where or why these and other stored data? I can not understand the logic of this error, after that from what I have installed and worked fine until recently.

Point out that I just installed FireBoard 1.6.4 available directly from the site,

Other components work well when the template check their minimal Kunena do not understand why after all the work done at night and Sunday morning because now I'm this big, but big problem.
Other forums do not work on a template and secondary developers even respond, but are not as important as Kunena, for the second forum I have to use an external forum for the other forum, when it is ready to share a bridge for users in before of what, the project will do without.
But now I'm still new.

Sorry for my bad English, I attach the image of another component that works well on the secondary template.

Resolved but do not know how nor by whom!
Hopefully it will not return the error in a mysterious way as it had arrived!