> Does anyone have ANY idea what is causing this? Would anyone have a
> minute to run the test case and verify it?

Just did it - with CONCURRENCY test case fails, works with CONSISTENCY.

> Could someone confirm that these are the correct settings for what I'm
> trying to achieve?

Why can't you use CONSISTENCY?

> Any ideas what I'm missing when it applies to 2 different connections
> created by the same DriverManager - why would it work creating it in one
> thread and trying to access it via isql, and not with 2 threads?

If isql, for example, translates SNAPSHOT + PROTECTED WRITE into
isc_tpb_consistency. I really don't know, whether that is the case, but I
also did not see in documentation that isc_tpb_concurrency can be used to
lock tables.

Roman