[SR-Users] General debugging and presence question

Hi All, Sorry for the general questions here, I'll try to be concise. I'm kind of a n00b, so bear with me. Problem: Kamailio will not respond or accept SUBSCRIBE. It kicks back a 404 every time. SUBSCRIBE is ok. Question #1: I actually copied a config from the vendor we are using and it's supposed to work so is there something simple I'm missing? Question #2: Logging. I've read that there should be a kamailio.log file somewhere that I can tail -f, but there's no such file on the machine. I've done a *kamailio debug -dd *but it's really tough to go through. Doesn't seem like you can grep using that either. If anyone out there has any advice for me, I would certainly appreciate it. Thanks!