Java Programming

Hi, so I'm developing a portal on a remote linux box and java is required.
I was changing and updating the database, restarted our server, and tried to boot up my portal again but got a seg fault.

I've tracked it down to java.
Every time I now run java I get an immediate seg fault.
I've changed the java_home and path and tried brand new and different versions of java, but every one is exactly the same - immediate seg fault.

I am really, really desperate for help. This is killer for my site, as it can't be up until I fix the situation.

Everything was working fine, so I must have done something, but for the life of me cannot think of what I have done.

If anyone has any ideas for how i can figure out what is causing a segmentation fault, I would be unbelievably grateful.

Thank you in advance for any help at all.
-Ed