Help! I downloaded the TP-patched version of HH95 and extracted the files into the same directory as the original JJ1 stuff. I also overwrote the files like "Jazz.exe" to make sure I could access all of the episodes from one screen. This did indeed work, and Holiday Hare runs fine... however, the other episodes are very buggy. Jazz is invisible when running or jumping, as are all of the enemies, powerups, etc.

Is there any way to fix this and still run both versions together?

JJ1 and HH'95 are not made to coexist.

HH'94 and JJ1 are compattable, though.