Are you downloading at 30 Kbps or 30 kB/s. Download speed on BitComet is usually displayed in kilobytes, kB/s, instead of kilobits, Kbps.30 Kbps would be about 4 kB/s. 4 kB/s is pretty slow, but 30 kB/s is fast for BitComet.
The issue with the seeds may be that alot of the users are in one area, and the time you try to download from them is a time when they're region is mainly offline(ex. night). It also depends on which site you use to search for Torrents.
TorrentSpy usually has a lot.
--Matt