The obvious physical things to look out for:
1) Cooling. The BPPC/BVision combo should definately *not* be used in a desktop case. They do fit physically, but thermally they are way outside the 1200's case design profile.
Still with the cooling, check under your PPC heatsink for dust and other crap. The "fanned from the other side" heatsink was a bit of a design error in that it traps dust like anything. Clean it out and reapply a bit of thermal paste.
If your 680x0 is a 68040, it won't hurt to put some cooling on that too.
The Permedia2 chip also gets very hot (so much so that you can burn your fingers). A heatsink there is a must IMHO.
2) Connections. Make sure all connectors are clean - botherboard edge connector, SIMM sockets and the bvision connector. Make sure the BVision is securely socketed. The MiniPCI slot can't take much physical load, so the whole thing is secured with a pair of screw bolts. Make sure they are holding the card solidly, but not tightened to the point they are stressing the PCBs.
3) Make sure your PSU is healthy. The chances that you are drawing anything like 100W even are not so great so anything over that is ample (excuse the pun). However, your PSU needs to be healthy - a good clean voltage level on all lines.
4) The BVision/BPPC combo draw more current via the A1200 motherboard than most other expansions. In some cases I have seen the effects of overload. It isn't a massive overload that kicks in the first time you switch it on, it's a slow "operating close to the limit for a long time" type of overload. This is only an issue when you are powering the A1200 motherboard from a single point of attachment (eg the original rear power connector). If you are using a tower expansion (as you should be for this HW), you can power the A1200 motherboard from both the original connection on the back, and also via the floppy power connector. This ensures enough current can flow into the motherboard but not all through one place.
Obvious software issues to look out for:
1) That your firmware is up to date. You should use the last flashrom update *before* the grexx one. Your 68040/60.library binaries reside in there so whatever you have on disk in that regard is irrelavent.
2) You have WarpOS correctly installed and with the appropriate termination settings. If you need any ppc.library applications to work, check out the ppclibemu package for warpos.
3) Not sure if this was fixed, but there are stack issues sometimes with PPC applications. A utility like stackattack can be useful - it patches the system to always allocate more stack that was requested.
