apache crashes; log says port 80 already in use

Hi,

I run an active forum on a virtual private server and suddenly have run into some serious trouble. My site went down yesterday, and when I investigated using SSH, I discovered Apache was not loaded, and refused to load, giving the error message:

"[crit] (48)Address already in use: make_sock: could not bind to port 80"

in the error log. I examined all the processes using ps and there aren't any instances of httpd running, nor anything that could be using port 80. After running out of ideas, I went through and killed every process running (save for ssh and my shell) and still Apache reported that port 80 was in use. Why could this be happening, and what would cause its sudden onset? Furthermore, how can I fix the problem? My host (iPowerWeb--oh how I hate them) of course refuses to help, given that it's a VPS. It looks to me like my server was recently restarted for some reason, since all the running processes have start times from yesterday, at (according to my fellow-admin) roughly the exact time the site went down.


Any help would really be appreciated.