I just upgraded to 9.2.1 the other day and while I haven't had major problems like others I do have one thing that annoys me: When I select my Mac OS X installation in either Mac OS 9 or X it reverts back to my Mac OS 9 installation immediately. It will boot into Mac OS X the first time I reboot but if I then reboot from Mac OS X it sends me right back to Mac OS 9.
In Mac OS X the Startup Disk control panel does not show the blue X on my Mac OS X system folder as it used to, but the orange 9 is still on my Mac OS 9 system folder.
I don't know what to do about this so if someone can help me I will be grateful.
My Mac is a PowerMac G4 533/DP with Mac OS 9.2.1 and Mac OS X 10.0.4 on the same partition. I used to have Mac OS X and 9 on separate partitions but it turned out to be too much hassle.