Has anyone experienced stability issues running Windows under VMWare Fusion?

I have attempted to install Vista Home Premium in a virtual machine within Fusion. Although it installs OK, it has frequently hung up the virtual machine, refusing to shut down, re-start, or go into suspend (even using the menus within Fusion to do this). This has been most prevalent since Windows Update installed a bunch of patches, but nevertheless it is certainly something that should not be occurring.

I don't plan on using Windows all that often (I would have purchased a MacBook Pro if that was my intent), but need it to run two relatively resource-light applications (my phone sync software and MS Money), and would prefer to open up Fusion rather than restart my Mac all the time. I noticed, as well, that suddenly Vista is taking up about twice as much space as before, which leads me to believe that something is causing it to thrash constantly to the disk (slowing things down).

I've increased the allocation of RAM to 1GB from 512MB, and set it to use both processor cores (from the default 512MB and single core), which doesn't seem to have helped.

Do you have a better experience installing Windows using Boot camp and then using Fusion to open up the Windows partition in OS X? Do you have any other suggestions?

I have a MacBook Air (1.8GHz with Hard Drive), and had set the size of the swap file to 20GB, of which Vista takes up about 7GB. I'm running CA Internet Security Suite within the virtual machine. I have Fusion 1.1.1 installed on Leopard (10.5.2), and have also installed the VMWare Tools within the virtual machine. If I go the Boot Camp route, I'll devote 25GB to the Vista partition.