3.0.6 crashes Vista64

[sagor]

I just downloaded the 3.0.6 version, and while installing on Vista64 Ultimate, it crashes (BSOD).
After going to restore point, 3.0.4 fails to run, giving "Unknown Error creating VM (VERR_FILE_NOT_FOUND)"

Result Code:
E_FAIL (0x80004005)
Component:
Console
Interface:
IConsole {0a51994b-cbc6-4686-94eb-d4e4023280e2}

So, seems like 3.0.6 may have a bug?? 3.0.4 has been running flawlessly for past 2 months.
Edit: Same error regardless of guest, XP, Ubuntu - all give same error

System is core i7, 12GB memory, Raid0, Asus P6T MB, ATI 4870X2 video.
How do I restore 3.0.4 to work again? Do I re-install it?
Thanks

Update:
I re-ran the 3.0.4 install, and did the "Repair" option. It successfully reset my current VM, and the guest boxes all work again...
The 3.0.6 install seems to fail around the network driver install - and Vista 64 still does not like it even after re-boot after failure. I had to disable the VM network device in device manager (in safe mode) to ensure a clean boot after the BSOD...

[vbox4me2]

We need more info, like any specific anti virus or firewall and such third party software in use?

[sagor]

anti-virus is Avira, firewall is Comodo. (free versions)
System and Application logs show nothing real unusual. One error about atikmdag, but could be related to re-starts. (ATI video card/driver/utilities?)

Otherwise, O/S is stock (Installed Aug5/09). Installation of 3.0.6 was done with no active windows other than the installer. Latest updates installed via windows update.

With 3.0.4, device manager shows normal Virtual Host adapter, but after crash of 3.0.6 install, the adapter had yellow exclamation mark, and vista kept trying to find the driver for it.

Hope that helps.