AutoCAD 2010 :: Repeated Fatal Error Messages

My co-worker and I have been getting Fatal Error messages a lot recently and there doesn't seem to be any consistent task that is causing them.  We've been getting the error messages with multiple different commands and multiple softwares such as ACAD 2009, ACA 2012, and ACAD 2012.  We can't seem to pin down anything specific that is causing the crashes.  Fortunately with my crashes I can simply restart the software and everything is ok.  However, there have been a couple of times that my co-worker's system crashed and he had to have ACAD 2009 re-installed (this is a major pain because we have to go through our IT department to get anything done on our systems).  We have different computers.  About the only common thing between us is that we are both running the same version of Windows XP on 32-bit systems.