I bet it's a driver.

by R. Proffitt Moderator - 6/24/11 3:40 PM

In Reply to: Acer Windows XP to Samsung LCD by Alxxxx2011

http://www.notebookcheck.net/Review-Acer-Aspire-5930G-Notebook.11910.0.html notes it came with Vista so pester the folk that put XP on this to correct the problem.
Bob