Read the forums and fix the problem with not being able to resize the screen in Ubuntu. There are dozens of complaints, and not one response from a Parallels tech with a solution. Do you just ignore posts until the users get sick of posting? If you can't resize the Ubuntu screen, the ability to create a Ubuntu VM is freaking useless!
Turns out it needs more video memory than the default 3MB. Virtual Machine > Configure > Hardware > Video (the VM has to be down before you can edit the setting). It worked for me with 12MB, maybe it'll work with less.