This drove me nuts! I run XP every once in a while and it was so quick on Virtualbox prior to the upgrade that I thought VB was the culprit.
I messed around with the settings, I turned things on and off; all to no avail.
Then I remembered a post somewhere that mentioned the video drivers. Not the virtual machine's virtual video driver, but the actual driver of the host machine.
So I looked at what I was running.
Nvidia's driver version 183 - which was suggested and recommended by Ubuntu 9.10 after the upgrade. It worked fine with everything I did... could it be the culprit?
I then swapped the driver to version 173 which I was running previously (that reminded me I tried 180 and had problems with virtual machines then too) and my XP virtual machine was happy once again.
I did experience an issue or two with my machine freezing (the whole thing, not the VMs) after doing this and thought it was the Nvidia drivers again.
However I noticed something interesting. The freezes occurred only when I had Firefox running. If FF wasn't running, everything ran smoothly.
So I went into the FF add-ons and thought about how a "new" add-on I had installed and almost never used would actually use cool 3D effects. I'm talking about FoxTab. I disabled that after 20 minutes and guess what?
My virtual machines are happy, my Macbook runs smooth as silk!
Now to troubleshoot something else... OpenVPN on NetworkManager.
-P
