Kubuntu no longer launches properly (Lucid 10.04 on Parallels)

[NonLocal]

The upgrade to Lucid Lynx from Karmic on Parallels Desktop 5.0 (see specifics below in sig line) was flawless, but when I restarted the system—and this has happened every time since the upgrade—the following happens:

Normal Parallels boot screen appears. This may be followed a very low-res Kubuntu boot screen which appears briefly. It then launches into several blink-and-you-miss-it messages.

Alternatively, several lines that end in the text "unreliable DMA position" appear.

In any case, after all that comes the following:

Ubuntu 10.04 LTS [computer name] tty2

[computer name] login:

After logging in and getting generic computer/login information and the "Welcome to Ubuntu!" message comes the following:

Your CPU appears to be lacking expected security information.
Please check your BIOS settings, or for more information, run:
/usr/bin/check-bios-nx --verbose

0 packages can be updated.
0 updates are security updates.

Running the above command gets me this:

This CPU is family 6, model 23, and has NX capabilities but is unable to
use these protective features because the BIOS is configured to disable
the capability. Please enable this in your BIOS. For more details, see:
https://wiki.ubuntu.com/Security/CPUFeatures

The problem is, this is a virtual machine and I am not given any boot options upon starting the VM (other than a checkbox in the "Configure" dialog to give me the option to select a boot drive). Help would be greatly appreciated.