Let be totally clear, some of what are saying to me is absolutely Greek. I appreciate you trying to help, but if you could dumb down some of your descriptions, or at least tell me where to look/what to do, that would be great.

The legacy app is constantly running. It is an automated dialer which retrieves data from remote locations and stores into database. It runs every day, all day long, with different times for dialing for different remote locations. There is no way of re-tooling the code for the legacy application as my company did not get all of the source code from the original developer, and what code we do have has little to no documentation in order to follow the flow (was written in Delphi in mid 90's). It doesn't make sense to me that the legacy application appears to be unphased by whatever is locking my new applications up!!! ??? Could it be that the old ODBC connectivity was more robust than the new .Net connectivity? Food for thought...

You say to disable Guardian. Do I do this by stopping the service, or is there another way?

Where do I find out if I am running Classic or SuperServer?

Yes, my patchwork apps are just as you described. They connect, do their business, and disconnect from the Firebird DB. Most of the time they are simply data retrieval applications for custom reports, spreadsheets, etc. Only one app actually inserts data into the DB.

Page size shows 16384 in DB Properties. If needed, where do I change this setting?

Dimitry Sibiryakov: Thank you for participating in my little game of "Let's Find the Obscure DB Problem". Could you explain "changing transaction isolation" for me?