Peer Sprite Viewer (what am I doing wrong?)

You should never have to go up that high, I mean a 4mb ROM only goes to 3FFFFF, and any compressed graphic(s) is no where near there. Do you have an example of what you are referencing? I suspect your may be looking at a document for a compressed part of C2 that deals with title screen gfx or something? I remember a disassembly where the addresses appeared to start with 7E-7F which I believe is 'SNES Memory', which I know little about, just that it's actually in the C2 bank and not 7E. Something like that anyway.