I have now also reproduced this problem on Windows XP.
To reproduce:  After getting an Internal EiffelStudio Exception,
click on the Submit Bug button.  Enter username "aaaaaa" and
password "aaaaaa" (presumably invalid) and click Login button.
When estudio reports failure to login, click OK, then click Cancel.
Click on Submit Bug button again.  Estudio reports an uncaught
exception (call on Void target in {ES_EXCEPTION_SUBMIT_DIALOG}.synopsis).
Full trace previously attached.