Thanks for this. Regarding your points:

1) The aging official Installer V43 (from Aminet) supports this construct - i.e. conditional (choices). I have already added a workaround for next IBrowse release.

2) This didn't change from IBrowse 2.4 to 2.5, and I don't remember any reports back when 2.4 was released about this. I don't have my BlizzardPPC system up and running currently, but perhaps I tested it there - can't remember if that still used the MUI: assign (I seem to recall there were two locations anyway). Anyway, I've fixed this issue for the next release.

3) All the images, including the toolbar? This could indicate a number of things. Basically, the pink background is the transparent colour, so somewhere in the system this is not handled correctly. First place to look is which PNG datatype are you using? WarpPNG, for example, will set bmh_Masking to mskHasTransparentColor and bmh_Transparent to the pink colour index, as do most other PNG datatypes on AmigaOS. It sounds like maybe this is not implemented in the MorphOS system supplied png.datatype.