Virtual PC and Mac OS X: do not install on the same drive?

Virtual PC should not be installed on any partition of a drive that has Mac OS X, even if that partition contains Mac OS 9. Although partitioning a drive will allow multiple bootable system folders, once the drive has Mac OS X installed on it, changes are made to all the drive's partitions. Jayson Lee writes: "I know Virtual PC does not work until OS X. So I installed it on my second partition after I had installed X on my first partition. Even though I'm booting up from OS 9 on the second partition, VPC still crashes. Connectix Tech Support told me that OS X can affect VPC even across partitions."

Update: John Melby writes: "Virtual PC 4.0.1 is installed on the second partition of my slave drive on which OS X occupies the first. It works beautifully when I boot into OS 9.1. My OS 9.1 Classic folder is on another partition on the master drive. I don't know whether this is an important distinction."

Update: We have heard from several more users, all of whom report no trouble whatsoever with VPC on the same physical drive as Mac OS X, sometimes on a different partition, and some on the same partition.