Larry has been patiently trying to help me with the network problem on my Ubuntu virtual machine (see the comments on Ubuntu on Parallels on Mac) He may have even found the problem.
But when I applied the fix and rebooted I was back to the problems from More Fun With Ubuntu on Parallels - unable to boot because the X display won't start. I did some more thrashing around and some more web searching. Lots of people seem to have this problem and there are various proposed solutions. I wonder if these "solutions" aren't really solutions - it just happened to work as it does for me occasionally. Frustratingly, lots of people also appear to not have this problem - it works fine for them.
This is on a Mac (mini) so you can't blame non-standard hardware. Ubuntu is one of the most common (if not the most common) version of Linux. I haven't loaded up OS X with a lot of junk software. So why am I still faced with these frustrating issues? I don't want to have to be an X Windows expert and mess around with xorg.conf. Running in a virtual machine adds some complexity, but it also reduces the complexity since the virtual machine is more "standard" than real machines.
I don't have a lot installed in my Ubuntu so I am going to try a fresh install. At least with VM's this doesn't mean I have to wipe out my previous one. It would be nice if Parallels had a prebuilt Ubuntu 7.10 VM but they only have 7.04. I could go back to 7.04 but sooner or later I'll want to update.
Some of my recurring frustrations are, no doubt, due to my staying to close to the "bleeding edge". But, (a) I want to keep up with the latest - that's part of my business, and (b) not doing updates has it's own problems with incompatibility, security, etc. and leaves you facing even scarier "big" updates, albeit not so often.