Comment 58 for bug 551013

This problem occurred for me, but I found a very good solution which I hope will be pushed upstream. The changes should be applied when proprietary graphics drivers are enabled and reverted when proprietary graphics are disabled. One of the steps involves choosing the ideal resolution for the splash screen, but since the system would most likely already be using the ideal resolution when the proprietary graphics driver is enabled, the installer could just detect what resolution is currently being used.

http://idyllictux.wordpress.com/2010/04/26/lucidubuntu-10-04-high-resolution-plymouth-virtual-terminal-for-atinvidia-cards-with-proprietaryrestricted-driver/