a big challenge: how to control toolbar's button size?

[skybirdcao]

I have big problem:

when I use CToolBarCtrl. I load a bitmap as a toolbar, and set button size as size (16, 15). At the beginning, the program run normally, but sometimes, the toolbar's button change bigger,
I don't know why.

The details link is: http://www.codeproject.com/miscctrl/PropEditor.asp

Maybe if you are a guru:cool:, or want have a try:^). Help me! Thank you very much!;P

skybird