Generally a windows .bmp file can't be wrong as well as 32 bit depth. Transparent color is not problem, any color can be used. Please wait for the beta version in order to see a new set of icons, which are already done (but some improvements might be desirable).

Jiri

For graphics, white kind of files are supported for the splash screen. Also, what bit level is acceptable for the icons: 16 bit or 32 bit? If 32 bit, is there a color that is interpretted as transpartent?