I used to have problems on my windows98/95 box where if the icon strip in the ide's source media (in the cfg directory) was either 8 or 24 bit images (I can't remember which but perhaps try changing the bit depth of those and it may start to work) then blitzplus (and blitz3d had the same problem) would fail when compiling or running within the ide and even running outside of the ide (executable).
Perhaps look into that?
Perhaps look into that?