About two weeks ago, I switched from Comcast high speed internet via cable modem to Qwest DSL. Now, when I try to download from BitComet, nothing happens. Status says “Connecting…” Tracker Status says either, “Connecting Tracker to Say Start, waiting for response” or “Tracker Response OK, reannounce in 300 s.” Anyway, it sat like that all day yesterday. I have downloaded the latest version of BitComet, so I’m assuming it’s something to do with the new DSL. Has anyone ever encountered this problem? I don’t have any firewall software installed at the moment…any help greatly appreciated!!! 
Check the BitComet log for any problems.
Also check the peers status for the torrent in question, and look at the number of seeds and peers shown. Too many sites retain torrents that are essentially dead - nobody has seeded them for a long time. These should be removed but too often, they aren’t.
You also need to consider your new hardware. Did Qwest give you just a modem, or is it a modem/router combo with a firewall? They often do the latter.
Very, very bad idea to connect without a firewall at all. Firmware firewalls are preferable to software, but you do need one (1) firewall.
The only thing that stands out to me in the BitComet log is…
“Windows XP ICS Status: cannot find working ICS.”
“Windows XP UPnP Status: device not found!”
Could this be a problem?
Probably not, unless you’re sharing your internet connection with another computer. If you were, you’d probably know it, as it’s fairly elaborate to set up. A lack of seeds/peers, or a firewall issue are the more likely problems.