Depending on what CD file system you use, there should be some option to cut filenames to 30 chars. In CacheCDFS prefs, the option is under 'ISO 9660'... In AsimCDFS Prefs it's almost the last page, under 'RockRidge Extensions' select 'truncate long filenames' If you have a different CDFS, check its' documentation....
And rkauer has a good point about decompressing the files on the Amiga, if possible.
Edit: Ack.. IIRC, there are other options to check in AsimCDFS as well...
