Andre,

Given your mix of versions I doubt very much if anyone else here will
be able to reproduce your problem exactly. I dont have Delphi3, I
probably have a copy of RB4 somewhere in my archives but dont have
time to try an reinstall for just this purpose.

I suggest that you take a detailed look at the callstack when the
exception occurs - this will generally give you some hint as to what
particular component is giving problems. Once you have worked out
which component/method then a breakpoint may allow you to discover
exactly which property is involved - and this may let you work out
how to work around the problem.

That is to say. I expect the problem is specific to your version
combination (I am using RB5 with IBO4 and Delphi5 without any such
problems). I suspect you will need to find a work around for the
problem.

Such a work around may include closing or unpreparing the query before
closing the report, or perhaps disconnecting the query from the
report. Lots of possibilities and probably only some patience and good
investigative debugging will reveal what needs to be done.

--
Geoff Worboys
Telesis Computing