Only the most recent added torrents actually download

[useruseruser]

I recently hooked up a belkin N+ router to my comcast internet, and I find that I can download torrents, but only the ones that are the most recently posted.... I have used mutorrent for a few years, and I could always get older files in the past, as long as there were seeders/peers listed. Now, many of the torrents have 0/0 seeders and peers (I read a similar post about someone who used comcast who had a problem with them dropping to zero), but I also have a bunch that say that there are peers and seeders, but they never connect. Also, all of my torrents say "downloading" even if they are inactive. I changed the global number of connections to be very low, changed download/upload speeds, and download/upload slots, but I still can only get a connection to very recent torrents. Mutorrent is in my firewall exception list, I am at a loss for what else to do. The old Belkin N1 router i had was acting funny (no wired connection worked, constant IP conflicts, etc) but it seemed to be able to get these older torrents. Anybody else have the N+ and have these issues? Or maybe not the N+ but Comcast? I also had to reformat my computer recently due to that annoying Vundo virus, and I did reinstall Mcafee virus software, but Mutorrent is listed as a firewall exception-I also manually forwarded my Mutorrent port on my router to my static ip address.... Help!