A lot has happened since I wrote last — among other things, I’m now with the MySQL organisation in the Enterprise Tools team, and one challenge this group is facing is the multitude of platforms being supported.
I needed to test a bug that to all appearences I had introduced, that was only manifesting itself on Linux; since (Open)Solaris is all I had at the time on the machines I use, and I couldn’t find a ready-made box running Linux, I had two choices: (re-)install a test box somewhere in the lab or use Virtualbox. I decided to go with the latter, especially as I could choose from quite a few canned OS images for Virtualbox here.
I selected a Ubuntu 64-bit image; download and installation on the lab machine went well, and I had it up & running after a fairly short time. One of the notices that Virtualbox showed me when it booted the Ubuntu VM was something about "mouse integration" being present. I hadn’t seen that active before, so I was pleasantly surprised that I didn’t have to press the host key every time I wanted to "escape" from the VM, as it were.
A few minutes after logging in the first time, the update manager told me it had some updates ready, did I want them? I said "yes" and let it do its work, including "reboot" at the end. To my dismay, when the VM came back up, there was no mouse integration — I had to go back to the old behaviour of pressing the host key… I had selected "don’t display this warning again" sometime earlier, and initially thought that that may have been the (unexpected) cause.
As it turns out, selecting "install guest additions" from the devices menu and then running the appropriate script got mouse integration back.