I've got a graphite iBook SE and have tried OS X a coule of times, first in the main partition, then in a second partition after I re initialized and partitioned the drive.
Now I am finished with X for the moment and have repartioned again as one partition in OS 9. When I boot I first see a folder with a question mark on it (couple of seconds), then I see a folder with the Mac 2-face on it, and finally the little old mac with the face onscreen. Everything else works fine.
Have I got anything to worry about?