Redmine

I am a redmine 0.8.7 user with a strange problem:

first i installed redmine on debian lenny and everything ran well. i used it trough apache with the dispatcher.fcgi file.
then i had to restore the server from a backup. after the restore process, some parts of redmine were incredibly slow, especially if you upload a file or a document or if you change or add a new ticket.

if you upload a file, the file gets uploaded very fast ( i see it on the files dir on the server ) but the http page stays white for another 30sec, then it succeeds or it brings up an error message.

i already tried to reinstall ruby, rails (diff. versions), apache etc. without success. .

here are my logfiles:

error.log
[Sun Jan 10 23:15:36 2010] [warn] (104)Connection reset by peer: mod_fcgid: read data from fastcgi server error.
[Sun Jan 10 23:15:36 2010] [error] [client 82.56.43.198] Premature end of script headers: dispatch.fcgi

production.log
nothing special

fastcgi.crash.log
[10/Jan/2010:14:19:41 :: 17622] starting
[10/Jan/2010:14:19:42 :: 17625] starting
[10/Jan/2010:14:22:45 :: 17619] asked to stop immediately
[10/Jan/2010:14:22:45 :: 17619] stopping after explicit exit
[10/Jan/2010:14:22:45 :: 13656] asked to stop immediately
[10/Jan/2010:14:22:45 :: 13656] stopping after explicit exit
[10/Jan/2010:14:22:45 :: 17622] asked to stop immediately
[10/Jan/2010:14:22:45 :: 17622] stopping after explicit exit
[10/Jan/2010:14:22:45 :: 17625] asked to stop immediately
[10/Jan/2010:14:22:45 :: 17625] stopping after explicit exit
[10/Jan/2010:14:23:22 :: 17952] starting
[10/Jan/2010:14:30:52 :: 17952] asked to stop immediately
[10/Jan/2010:14:30:52 :: 17952] stopping after explicit exit
[10/Jan/2010:14:30:58 :: 18532] starting
[10/Jan/2010:14:32:20 :: 18532] asked to stop immediately
[10/Jan/2010:14:32:20 :: 18532] stopping after explicit exit

any solutions?