My Inspiron 1000 did this for a while once also.  I found out that it was adobe type manage that was doing it.  If you have that installed then uninstall it and get the newest one from www.adobe.com and that should fix it.  It did for me at least.

If you still want to use Adobe Type Manager, you can install the most recent version and it will still allow you to use hibernate.

Thanks....I searched the forum and found my exact message.  You  were correct about Adobe....we had installed an old photo program that seems to have caused the problem.  We un-installed the program and used a registry cleaner and the problem is solved!  Thanks for your reply.