» Sat Feb 19, 2011 12:28 am
You may have to manually clear the local content. Someone posted a thread on how to do this on the release day, or right after but I can not find it. However the OP in that thread cleared the local content and it stopped the downloading from Steam.
However it could also be because there was a large patch that came out right after release that for some folks is 2.5 GB in size, so that could be what it is downloading. However I have not seen that on my machine (could have done it in the background for me) so I am not sure if that is the answer.