After rolling back to 4 some months ago and no longer experiencing the problems, I decided to try upgrading to 5 again. It was kind of like getting too drunk and ending up with a hangover... you know how you get a hangover and swear you'll never drink again, but then inevitably you forget how bad the hangover was, and you get just as drunk, and just as hungover again.... well that's how this was. In the 3-4 months since I first commented on these problems, there have been zero upgrades or patches for fusion, that I can see.
Best I can tell, VMware doesn't seem to care at all for the folks who are having any of the apparently numerous (but admittedly difficult to replicate) problems since upgrading.
One question I have for the community: has anyone noticed this particular problem with a brand new VM that was installed/created in VMware5?
I'm wondering if the issues I'm having are a result of the upgrade itself, and whether they might not occur if the VM is created with version 5.