> Simply removing these two things gave no improvement at all.

I'm glad of that, I did not want this new feature to break anything
yet :-)

> It seems that the only way I can connect cleanly is to have
> nothing in the Params property, set PasswordRemembered to
> false, LoginPrompt to true and let the user login via the
> dialogue box.

Have you tried setting the Username and Password properties at runtime
(in code)? At least by doing this you are avoiding the possibility of
some sort of DFM/resource mixup. I would also suggest that this
approach would be a good idea anyway, since it will be IBOv4 "safe",
it would also allow you to tie the username/password to a registry
entry (scrambled or otherwise) to avoid hardcoding such aspects.

When running the application within the debugger, when the logon
exception occurs note down the full call stack. Particularly noting
what units, classes and instances the various functions are coming
from. If you can find a call from TIBODatabase or TIB_Connection then
set a breakpoint in that function. When you run the application the
second time it should stop at that point and you can setup some
watches to see where things are. You should be able to setup watches
to determine the name of the component (to ensure it is the same one
that exists on the form) and possibly a few other things as well -
password, username, params etc.

Maybe this will reveal something.

Geoff Worboys
Telesis Computing