For some reason, on my machine, the selection of the display size doesn't stick through a reboot - it's a nuisance to have to reset that resolution setting each time I start up. This is in VirtualBox, with a resolution set to 1280x1024 which on restart sets itself to 800x600. Why would this be?

This was a tough question? Or has support on here dried up?

Lol. I think they're just busy with the upcoming new release. Hang in there; Eric's got his hands full.

You can try creating an xorg.conf file and putting in the desired resolution.