Problems with toolbar images

Hi

I have some problems with the following example.

http://bioinformatics.nyu.edu/~marcoxa/common-lisp/code/toolbar-test.zip

What happens on LWW is that the interface works fine, but the two 
buttons I load appear black.  I tried different values of 
:transparent-color-index to no avail.

Also, some of the .bmp files I created using MSVC++ and Paint refuse to 
load (I get an "Invalid DIB file" error).

Does anybody have an idea about what is happening?

Thanks

--
Marco