On a couple of occasions when researching crash problems on my G4/400 Yikes, I have seen a strange phenomenon. If I try to invoke Conflict Catcher 8.0.6 during startup (using either space bar or caps lock), the Mac freezes just at the point where CC should open, with a message that the CC Extension has a problem (unimplemented trap or whatever). If I then switch to Extensions Manager, exactly the same thing happens, only now the OS blames the EM extension. No matter how many restarts are tried with any extension set except "shift key disabled", the problem persists, even if CC or EM are NOT invoked during startup.
After a bunch of trouble I discovered that the fix for this situation is to shut down the G4 and leave it shut down for half an hour or so. Restart and the problem has vanished. What's going on, and why does leaving the Mac shut down for a while fix it? This has happened on two occasions now.