need help debugging session problem

[Andrew Draskoy]

Each morning all our users cannot access IMP.  They are greeted with
"ORA-03113 end-of-file on communication channel" in each window.  After
some undetermined period, the problem goes away, to be repeated next
morning.  This is stopping us using IMP in production.

It appears to have something to do with session info or cookies being
kept from previous attempts, but the corresponding oracle connections
no longer being valid and the oci8 driver not checking for this error.

I'm attempting to debug this, but I'd appreciate some suggestions for
approaches from someone more familiar with the code.

Thanks,
Andrew