While dealing with the desktop rebuild problems on my 3400 (running Mac OS 7.6.1), as just noted, I first became aware of several other conflicts (which probably predated the desktop problems). It took a long afternoon of using Conflict Catcher to work all of it out. The causes of some of them were a bit strange and unexpected. For example:
1. Power key and CyberFinder When holding down the Power key, the message that should appear (asking whether you want to shut down) no longer appeared. Disabling CyberFinder brought this feature back.
2. CD-ROM and Profiler Apple System Profiler froze on launch. Conflict Catcher claimed that this was due to Apple's CD-ROM extension. Indeed, disabling these files allowed Apple System Profiler to run (although it still reports my startup device as "unknown").
Update: I have tracked down more about this curious problem. I have reported the details to Apple and await a reply:
a. As stated, it does not happen with the Apple CD-ROM extension disabled, even though Profiler can still detect the CD-ROM drive.
b. It does not happen even with Apple CD-ROM enabled, if there is a CD-ROM disc in the drive.
c. It thus only happens when the extension is enabled (even when all other extensions are disabled) and the drive is empty. I am using a 12X drive.
3. Type 10 errors and Sleep I periodically get Type 10 errors in the Finder immediately upon the 3400 waking from Sleep. Conflict Catcher identified a QuickDraw 3D file (QuickDraw 3D IR) as the cause. Disabling this extension did seem to eliminate the errors, but I am fairly certain that there is still more to this problem.