First, thank you both for supporting me in this case (: Actually my totally lack of C knowledge is something i have to work on asap. -- Rob, i have tried your patch and it fixes the problem. seeing my mistake using TBUTTON_INFO as TBBUTTON makes me realize that i wasnt at least too far away from the right track. By the way, your implementation of ImageList_SetColorTable also works fine for me.
I still have one question regarding the relation of NMTOOLBAR.pszText and TBBUTTON.iString: You did not use nmtoolbar.pszText here. Is it optional, because its already in the TBButton struct ? If yes - what about nmtoolbar.rect then ?
Tho