I haven't been able to reproduce the problem. Initially I thought it was another symptom of the 0x0 access violations related to Oracle 10g, but 6.0.6 seems to have resolved the 10g issues.
Unfortunately, although the log file exists, the last log entry in it is from Aug 23, the failure above was never logged.
I haven't seen this crash since my original post, I will post another message if it happens again.
This might be related to Access Violation with Oracle 10g Rel.2 . I am getting an application error with version 6.0.6.943 that was released to fix Oracle 10g issues.
I was trying to close one of the SQL query windows within PL/SQL Developer and it crashed after answering no to the "save...