No, I got both Parallels and Fusion working fine as independent VMs. My root problem is that both are significantly slower operationally than the same setup in Bootcamp.I knew this from a theoretical POV going in, but experiencing it is something else. Everything just slows down--starting programs, saving within programs, switching programs, moving stuff, changes places within programs, etc. It's sort of like taking a step or two backward in hardware, and then, when you boot up Bootcamp again, everything runs like lightning.
On top of that, I had troubles with both Fusion and Parallels. As I reported in another thread, I tried Parallels with my prior Bootcamp installation, and it some how screwed the Bootcamp install. So much so that eventually I had to reinstall OSX (because after I'd removed my Bootcamp partition and gone back to an all OSX hard drive, DiskUtility returned an minor error that seemed to stem from Parallel mess. Eventually I corrected the error by booting off a backup, but Bootcamp would not repartition the drive because of some error, even though Diskutility reported the error as having been fixed.
With Fusion, I started getting strange messages about problems it was having booting. But then I restarted OSX and it worked fine again, so I don't know what the problem was.
Eventually I decided that I did not want to run the risk of having either Fusion or Parallels go south on me, so I went back to Bootcamp, which I'd previously used for a year and a half without incident.
Now I'm thinking about just having an OSX connection to my Bootcamp partition for those times when I'm in OSX but just need to jump into Win for a couple minutes or so, and would prefer not to reboot.