Uncharted caption: "Does my armpit smell that bad?"

Does anyone hav a problem with running High Detail Shaders on? As soon as I put it on i can't load my saves and if i activate it durin gameplay it freezes afta approx. 20mins. My specs are: Windows Xp SP 2 AMD AM2 Dual Core 3600+ nVidia 7900GS 256mb 1gb ram