PHP extension dlls seem to get changed?

Hi, I have apache 2.2.3 running on windows server 2003 with php 5.1.4.

A couple of times now, Apache has "performed an illegal operation and must close" and I dont know why. I can't seem to find a solution in the error logs either. But the problem is, when this happens I cannot get Apache to start again, until I either comment out the extensions from the PHP.ini OR replace the extension dlls being used by PHP.

As soon as I have done this Apache continues to run. Any information as to why this might be happening and how to fix this would be appreciated.

Thanks

Luke

The apache error log gives me:

[notice] Parent: child process exited with status 4294967295 -- Restarting.

However, it fails to restart. I have read that the error happens when a DLL calls exit(..) and forces the apache child process to quit.

In all cases I've read about, the server restarts successfully when this happens. In my case however, the extension dlls being used by php get changed in some way.

Still very confused... any help would be great.

Thanks

Luke