There is a limit of 2MB max per ID3v2 tag. Anything bigger - and OrangeCD Catalog will refuse to read it. It was made for protection against corrupted files that could eat up a lot of memory (and make Windows 95/98 systems unresponsive). 2 megs are more than enough for a decent image scan in JPEG format.

How big were your images? Maybe, instead of downsampling you could just re-save them as JPEGs if they were in a different format.

Andrei