To both of you-
I have found that WMP pretty much sucks for playing previews or anything else. Half the time it will give errors(usually pertaining to codecs), or it will have trouble opening the file period. Suggestion- Get a new player!
Winamp will play pretty much any file type without much fuss. You might also search the forum for other players that people prefer, and if anyone has a suggestion, please reply to this post.

Sketch-
It depends on how much of the file has been downloaded. If you only have 1% or 2% it usually won't play it. I can't tell you if that file is a fake or not, I don't have it. The t-XXXXX means its an incomplete file. One way to tell a fake with those types of files, the real ones usually have fairly large file sizes 450MB+. If you're not sure about a file, let it completely download, then use your virus scanner to check it before trying to open it. Also, when posting, try not to mention file names please. That is one of those things that's mentioned in the forum rules that I'm sure you read.

Ranger-
If you made sure that all of the boxes are checked in WMP, you might want to go into the options for Jasc, and make sure the different MPEG file types are not set to open that application.