Transaction oddities?

Hi. Relative newbie here.

I'm using the Perl DBI:ODBC (ActiveState Perl 5.8.0) to work with my
psqlodbc DSN (on Windows 2000 SP 4). This generally works fine.
However, I'm having some weird behavior that I haven't seen before and
can't easily test in an alternate configuration.

My script reads information from a Paradox table, formats it, and pushes
it into PostgreSQL tables.

I have AutoCommit turned off. My script performs a variety of UPDATE
and INSERT statements within the same transaction. Then, once finished
altering data, it uses a verification routine to compare the results of
the operations (by SELECTing from PostgreSQL) to the source data.

All of my UPDATE and INSERT statements go through fine. However, when
my verify routine tries to SELECT the data they added/changed, it can't
see it. What makes this weird is if I change the order of events so the
verification of a particular record occurs IMMEDIATELY after the INSERT,
the SELECT does see the new data. Ordinarily, the verification occurs
only at the end.

And of course, the transaction isn't committed or rolled back until
after the verification step.

Maybe this has nothing to do with psqlodbc, but I can't tell. I've
tried using SET TRANSACTION ISOLATION LEVEL READ COMMITTED to no avail
(but that's the default anyway, isn't it?)

Any ideas or mockery or whatever would be greatly appreciated. Thanks.

Ethan Rowe
Information Systems Administrator
National Braille Press
Boston, MA
617-266-6160 ext. 35
erowe(at)nbp(dot)org