DREAMS CRUSHED!!

Recently picked up a JAP Zombie Revenge, when it arrived I popped it into my PAL DC via the DCX boot disc.
Appeared to be fine, played the 1st mission no problems, but as soon as the episode 2 screen pops up I return to the DC menu screen? Disc looks fine, tried again and same issue :s

Thinking this was FAIL I fired up my JAP DC and tried again...
With this console the episode 1 screen came up after the intro FAMMYDODD'ed back to the DC menu? Whaaa!??!


So I then tried the rest of my NTSC-J games on the JAP console:
SFZ3 - resets wont play?
Biohazard 2 - dies after the intro movie?
PenPen - resets wont play?
All Revert to the DC menu screen?

Space Channel 5 - fine
Cap Vs Snk 2000 - fine
Soul Calibur - fine
F355 - fine
Daytona - fine
BioHazard CV - fine
Crazy Taxi - fine
Sega rally 2 - fine
Marvel Vs Capcom2 - fine

Wtf is happening?

PAL DC, so far has played:
(J)Cap Vs Snk 2000 - fine
(J)Soul Calibur - fine
(J)Daytona - fine
Giga Wing - fine
Gunbird - fine
Bangai-O -fine
Virtua tennis -fine