HD TV channels on a data-only cable package?

Sounds to me like the first time around they put didn't put a trap (device that filters out TV service) on your line, but this time around they did. Your option at this point is limited to setting up basic cable. However, there may be a bundle discount available where having internet + TV is around the same cost as having stand alone internet.

Yep I'm with jz. The reason that you're getting any tv signal is because they haven't converted their signals to digital signals (that require a converter box.) They've probably made the transition to HD signals. I have RCA in NYC and I can't get anything at all by sticking the coaxial cable into my tv. What I do recommend is getting an antennae. With a very basic antennae ($10-$20) you can get cbs, nbc, fox, abc, my9, cw, and pbs all in hd and all for free.

Don't buy an antenna- Make one yourself from coat hangers using http://www.google.com/search?q=coat+hanger+HD+antenna. it took me less than 1/2 hour and out-performed the Radio shak one I used first.

Thanks, everyone! I'll give the coat hanger a try :-)

Followup: I thought they were obligated to provide the clear QAM channels for free. Is that only via broadcast?

Yes - cable cos are not obligated to give out anything for free. They would take away your access to even the non HD channels if they knew you had it. However, with analog cable its oftentimes hard to detect.

In the past some cable companies chose to offer basic cable as a "bonus" for subscribing to Internet service. (they figured it was cheaper to pay the content owners than to roll a truck to stick a trap on your line) In any event, they are required to offer local broadcast channels in clear QAM as part of a basic cable subscription. Internet-only doesn't cut it unless they specifically include basic cable as part of that offering. If you are supposed to be getting basic cable as part of your Internet subscription, they've probably moved them to new frequencies for whatever reason, which may be filtered by a trap on your line designed to prevent you from getting analog expanded basic.

If I'm not mistaken, the cable cos are generally required to broadcast local channels in clear QAM. I have an internet-only plan in CT with a different cable co, and I get the NYC locals (2, 4, 5, 7, 9, 11, 13 etc.) in HD off my cable via a splitter. That said, I think there may be an exemption within NYC itself which allows the cable cos to encrypt local tv due to its availability over the air. The OTA signal should provide better quality (i.e. less compression) anyway. The go-to site on this stuff is avsforum.com. http://www.avsforum.com/avs-vb/showthread.php?p=19413837#post19413837 is their designated thread on Time Warner in NYC. Expect lots of discussion about what's available via the QAM tuner there.