Apple does not support multiple Boot Camp partitions or the use of rEFIt and in turn neither does VMware Fusion much less VMware Fusion doesn't properly support a single Boot Camp partition. In other words in regard the latter part of that statement...
Fact 1. Apple doesn't guarantee the BSD Name of a Disk between reboots.
Fact 2. VMware unfortunately and inexcusably was unaware of this when they designed Fusion and as such when OS X assigns a different BSD Name to a Disk then it previously had and when this Disk has a Boot Camp partition that has already been prepared to run as a Virtual Machine then two or more entries for the one Boot Camp partition can and will appear on the Virtual Machine Library in all versions of Fusion to date.
Fact 3. VMware has been promising to fix this in a later version of Fusion for almost 3 years now and still hasn't fixed it!
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This is more prevalent on with a Mac Pro however I've experienced it with a MacBook Pro and especially when having external drives attached that have a Boot Camp partition on them. On a Mac that has a single hard drive and only a partition for OS X and a partition for Windows it's less likely to happen compared to the Mac Pro which often have more then one internal drive however I have experienced it on a MacBook Pro in of by itself however it is more likely to occur when multiple hard drives are in play.
AFAIC Until VMware corrects this issue it is not worth using the Boot Camp partition as a Virtual Machine and I went so far as to, with Fusion closed, rename "/Library/Application Support/VMware Fusion/vmware-rawdiskCreator" so Fusion would stop enumerating the Boot Camp partition and placing an entry on the Virtual Machine Library. I then deleted the "/Users/$/Library/Application Support/VMware Fusion/Virtual Machines/Boot Camp/../Boot Camp partition.vmwarevm" Virtual Machine and opened Fusion and deleted the Boot Camp partition entry on the Virtual Machine Library and will not use it on the Boot Camp partition until VMware fixes it!
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As to the use of rEFIt, VMware Fusion may not be able to properly prepare the Boot Camp partition for use as a Virtual Machine and this could then require some advanced modifications using Terminal and various Unix commands and of course is not supported.
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I started with Parallels years ago and switched to Fusion when it first came out and while I found it to be lacking in many features offered by Parallels as well as VMware's own Workstation product that I've used for over 5 years and continue to use on both Windows and Linux Hosts none the less I uninstalled Parallels and at that time didn't look back until after Fusion 2 came out and while I have used Fusion 3 too I no longer use it as my primary virtualization product on my Mac and have switched back to Parallels 4 and will go to 5 shortly. That said however I'd suggest that you download Fusion and take advantage of the free 30 day trial and see how you like it and if you'd prefer it over Parallels. I'm a firm believer of trying what's available and see what work best for oneself and go from there.