Problem with start-up disk



I can't switch from OSX to OS9 or OS9 to OSX, in a partitioned disk, whatever the attributed partition (first or second) to the OS.

I've installed OS X on a Beige G3 266, original ATA disk 4GB,
with USB + video compression PCIs, 96Mb RAM. I've done two partitions, one OS 9.0.4, the other OS X. In OS X manual, they say that the first partition must be OS9. Doing so, in OSX System Prefs, if I choose OS 9 as start-up disk then reboot, reboot fails, the screen shows a disquette with question mark, until I insert the OSX Install disk, and everything has to be installed again...
In an Apple online information, they say instead that with an
original ATA 8GB disk, OS X must be in the first partition. I did so, and indeed as I chose OS 9 as start-up disk in Sys Prefs, my Mac rebooted on OS 9. The problem is that I can't go back to OS X from OS9, because the control panel refuses selecting the OSX disk, with a message like "system lacks resources to start from this disk". Does anyone know a way out?
OSX works however wonderfully well, except the previously known incompatibility with USB card adapter (I can't print if not in OS9!)

Originally posted by cbaron
Use the /Mac OS X/Mac OS 9/System Disk app...

Thanks for the info - I disk-overed the app by chance a few days ago in the OSX CD-Rom.
Hell, why don't they put it clearly into evidence in the installation manual???