Not monitor related.
Anyway, do you use TeraCopy? It seems that it's a very common problem with it. The solution is usualy to uninstall it totaly.
From the reviews I've seen, it's often slower than the plain windows copy process and less reliable, especialy when moving fIles around on a single drive. In this case, it can be literaly 1000's time slower when using TeraCopy...
Electro
August 2011