I don't know if it was only affecting CD transfers, but in addition to causing DiskCopy checksums to fail, it also stopped Mac OS 8 from installing from CD (it failed part-way into the Mac OS install with an error). It took a while to narrow it down to the L2 cache as I was testing all the new stuff.
The thing is, I have a cache module for my 5400 which also misbehaves if it's installed. I could never figure out why. So I have cache modules for both of my OldWorld PowerMacs and neither are currently in use.
If the memory test passes the cache module then what else could be at play? Is there any voodoo involved in getting them to work OK?
The Orchard: 7500/100 - B&W G3 (x2) - G4 Gigabit Ethernet - iBook G3/500 12" (Dual-USB) - Black MacBook 2,1