Very strange, indeed.

Possibly your ISP? I was amazed to find that I could not get to a download page for LW on my friend's machine. I could get to every other page at LW. Same thing with Frostwire. The ISP (MSN) was blocking particular pages (we were using IE6 or 5).

Your ability to work around the problem suggests you are probably right about it being a charming addition to IE7. Makes me think I should start using Opera.

If the torrent site has a forum, you may want to ask other IE7 users if they are able to download the torrent, or if they have noticed other quirks. The RIAA has had a few changes in their strategy lately. And I trust MicroSoft only slightly more than I do the US gov.