If it involves downloading from the site:  Have you tried lowering your Internet Security settings and then try to download something?  And did you also make sure to turn off any download accelerator programs you have installed?  :angel:
If it's a game problem:  Make sure you have extracted the files from their compressed .zip or .rar formats into the correct location:  
C:\Documents and Settings\*your user name*\My Documents\EA Games\The Sims 2\Downloads.  If they haven't been extracted, they won't show up in game.  
