> I'm running a Delphi app against Firebird 1.5 RC9 and I am getting
> occasional errors of the following form:

> ISC ERROR CODE:335544332
> ISC ERROR MESSAGE: invalid transaction handle (expecting explicit
> transaction start)

> My Delphi app is multi-threaded. I have ensured that each thread has
> it's own connection, transaction and session component.

My guess is that you have an execution path through one of your threads that tries to execute a SQL command without calling transaction Start() first. Are you positive that there is a Start before any SQL operations after you do a Commit?

HTH,

Dan.