IPS Driver Error - Cannot Create New Posts

I'm having problem with my IPB forum which runs on MySQL database (hosted on linux Fedora).

Our website was unavalable for a short time, and when it came back on-line, we found we cannot create new topics/add replies, in short, we cannot add new records to ibf_posts table. However, editing existing posts works, sending private messages works, so database seems mostly OK, apart from posting. Whenever we try to post/add new topic, we get IPS Driver Error. We have tried restarting MySQL several times, but it didn't solve the problem.

Looking at the error log, we notice the following lines (but we're unsure is it about this problem):

Quote:

[Sat Nov 01 19:32:06 2008] [error] server reached MaxClients setting, consider raising the MaxClients setting
[Sat Nov 01 19:39:25 2008] [error] mod_fcgid: fcgid process manager died, restarting the server
[Sat Nov 01 19:39:36 2008] [warn] child process 2281 still did not exit, sending a SIGTERM

and then several hundreds lines like this:
Quote:

[Sat Nov 01 20:21:53 2008] [warn] child process 26643 still did not exit, sending a SIGTERM
...
[Sat Nov 01 20:21:56 2008] [error] child process 26643 still did not exit, sending a SIGKILL
...
[Sat Nov 01 20:21:57 2008] [error] could not make child process 26643 exit, attempting to continue anyway
...

It seems really strange that forum and database seem absolutely OK, that editing and private messages work (and Admin CP seems fine) but that it throws IPS Driver error on new posts only?