1) Do you have your screensaver set to automatically come on after a relatively short period of time? If so, try setting to something like 1 hour.
2) Are you still running Linux on the machine? There are suggestions for upgrades if you google "MSI wind netbook screen flicker problem." There's also a Windows fix here: http://www.pcurtis.com/wind.htm (scroll down a bit.)
3) Are your power saving features enabled?

Hope that helps.