Test your SDRAM, before you settle for Celery.
Some PC100 will run 133 at CAS3, or even CAS2. It just depends on when and by what company your module was made, and what chips they decided to stick on it. Find a friend that has a stable 133 rig, and ask him/her if you can plug in your PC100 to test it out.
Good luck,
Nack