On all FTA sites there are irresponsable people who post fake files. How you can sort them out is, look at the numbers of posts and Rep points, that he/she has, the higher the number of posts/Rep.Points the safer you are. The person who posts fake/bad files typically posts the files first (because the fix is not out yet) and he/she has only a few posts, and few if any Rep.Points. If you use this method it will greatly reduce your chances of getting a bad file.

Warning Flags;
The first "FIX" posted for that ECM and receiver.
The person posting has few (if any) "Posts" and "Rep Points"