I think i have an idea whats wrong with the windows opened later! nothing to do with the window itself.. and also this error messages seems have nothing to do with it.
the Hook which call the opening of the window seems not working well… even I can not explain whats the reason.. I wrote a little Mui only program (so without LCL) and i got the same result.. when i produce a new window inside the button click.. this Window will crash (little bit different behavior, other memory areas).
Then i tried not to use a THook for calling the button press but a application Result (as is used for Quit the program).. and IT WORKS, without any problems… ok this way is VERY bad to use in LCL because very hard to find who made the call (make a separate list?).
Ok as a first tryout I COULD try out tomorrow… hmm or try to find why the Hook makes such bad things… hmm perhaps a gdb debug would help.