> Is there a debug version of Jaybird?

JayBird is compiled with debug information. Sources are also available for
download, also you can get them from CVS.

> I could send you the DDL for the table, but much of the data is
> sensitive.

DDL does not help. I would need data, even dummy ones (important are IDs and
dates, rest is more or less garbage from my POV).

> And since this only fails sometimes, given my luck you
> wouldn't be able to reproduce it.

That is bad... If this is not reproducable, then it can also happen that in
Database Workbench you're just lucky...

Try asking about such SQL construct in Firebird-Support, maybe you get more
information there.

Roman