September 06, 2011, 10:09:08 am
Have you tried using the Low Memory Mode in Settings?
By the way cant find as listed product a GeForce 250MS, is it a GeForce GTS 250M? in which case any 200 series is way below minimum specs for LUmion, not that it might not run as you found SP1 did.
SP2 should be quite a bit faster, not the otherway around, what mage Quality display level are you running at in Build Mode, you will probably need either Level 1 or 2 at most.