Beige G3 MT Boot Problem

[Lorri Carr]

I have installed OS X on a number of Beige G3 desktops and minitowers 
without any problem. For reasons that suit my computing,  I create 3 
partitions: OS 9, OS X, and Storage.

One minitower has exhibited a strange behavior. If I boot into OS 9, 
then later try to boot into OS X, I cannot do so. Here are the steps 
taken:
  - In OS X, select OS 9 partition as StartUp Disk.
  - Restart to boot into OS 9 and do what needs to be done.
  - Go to Control Panels and select OS X as StartUp Disk.
  - Restart to boot into OS X.
No soap.

I have also tried shutting down instead of restarting and using the 
Option key on start up. In order to boot into OS X I have to reinstall 
Jaguar. This was not a one time anomaly; the problem will repeat. Both 
partitions have up to date software, X is installed on the first 
partition, and firmware is up to date.

Any idea what the problem may be?

TIA,
Lor