Hmmm that is exactly like mine looks .. is the Type on the bottom label:
UH-204 ??

:)

Well speaking of USB for Mac or PC, there (hopefully ) is just one flavour of USB, but you can construct USB devices the way that they are recognized correctly on both OS's or just on one or on no OS, if it is not recognized correctly, it needs special drivers ( or at least an inf file ) on WIN 9x ...
Maybe this is the case for your HUB, but ...
sounds silly, but why don't you ask at the place you bought it ?!

Nils