1st of all..it's not a bug. If you use another or a different mame binary, ClrMamePro checks if the cachefile is ok for that binary (some checksum check does that). If it's valid for the binary, it loads the cache, otherwise it creates a new cachefile for that new binary.

2nd of all...you can easily change the cachefilename. Simply add entries for other mame binaries to the end if engine.cfg. Like:

engine (
name "MAME WIP"
cachefile _mamewip
command -listinfo
)

etc...

Roman Scherzer
ClrMamePro