Thx for trying to help me out.
I tried everything, erased everything, rewritten everything,rebuid dll, renamed dll,.........
I also build different dll's for AutoCad 2010,2011,2012,2013 32bit/64bit and every dll loads just fine.
When I launch these dll's from the commandline (with cmdtest or (command "cmdtest")) on different Autocad versions.... no problem.
But adding it to acad.lsp or acaddoc.lsp or S::startup or a lisp that is being loaded from a *.mnl file with the same name as my cui(x), AutoCad just won't run it automatically.
And what is very strange: everything I try in AutoCad, I also try in Bricscad (of course with other refferences in the dll), and it works 100% in BC.
I don't think there's is much more you can do for me,
Thanks for your help and time, I really appreciate it.
If I ever find the solution, I will post it.