Repairing disk permissions is unlikely to fix an issue like this...
But- Go to Applications/Utilities/Disk Utility
Click your volume in the box on the left side of the window, and then click "Repair Disk Permissions" in the main portion of the window.
A lot of folks tend to rush to Repair Disk Permissions as a fix because it's easy, but it really has nothing to do with a situation that would cause items to transfer slowly IMHO.