Error 500

I've been experiencing a discontinuity in the service since I set up my forum. I simply installed the phpbb package, set it up without any additional packages and I did not touch too much in the source files (just changed the logo). Anyway, quite everyday people (and me) are often not able to see the forum. The error is "error 500". I tried to follow the instruction, deleting the content of .htacess, but it didn't work (then I re-established the old version I previously backuped).

This is the forum
http://airicerca.altervista.org/forum/

Any suggestion?

Many thanks
Salvatore

[Gianluca]

airicerca:

the issue should have been fixed now. If the problem persists please let us know and post the exact time when it happened.

Many thanks for your help

Salvatore