WoW choppy and a errow message

[Darkkon]

I hope this is the right area to post this. My problem is with World of Warcraft every time I start the game i get a change hardware pop up and i hit yes and it loads up and it is choppy and sometimes dark and i get a message like this one below

[String"Interface\GlueXML\GlueParent\.Lua"]: 143 Alpha must be in the range of 0.0 plus there is 2 numbers behind the okey button that i can not read.

All my other game work fine like F.E.A.R. and Far Cry and anything else i play on my computer. My Spec are in my sig.

Thanks for the help if any knows about this problem