Very true. Don't expect it to sit on that specific port. However, if pccillin found it, there is a good chance that it is running on that port. Unless pccilling flags on packet payload rather than source/dest ports. Either way, if you see some ports open that you cannot identify after doing a netstat, then subseven could be running on one of those.
My advice to a noob would be to become very familiar with what software you have on your system and know how it behaves (what ports it uses, what processes it starts, etc). This way, you can definately spot when things are running amiss on your box.
