Yes, that works just fine. But you can't expand the main partition back that way, since Disk Utility can't enlarge partitions, and Boot Camp Assistant (which can expand it,) doesn't see the partition anymore.

Click to expand...

It'd be easy enough to pull the second partition back into first using fdisk or parted (off of a linux/bsd install/recovery disc) if you needed, but I don't know what OS9 or OSX would think when it saw the drive.

Nathan