I have a MSI 6570g (k7n2g) mainboard and just downloaded Ubuntu 11.10. It booted from the CD, when through the progress bar but at the end the display just showed colored stripes. The system works with XP Pro SP3. The video is just the on-board video
When the disc is booting and you see the man and the keyboard, press any key. Select English, then press f6 for options. Use combinations of nomodeset and acpi=off and noacpi until it boots without lines.