Random Loop on "OPTIONS /w/" causing high CPU Load

It seems like this problem keeps showing up for me, but I'm still not sure why. I have disabled the WebDav module, but randomly on a page access my server seems to go into a loop with apache2 making a HTTP OPTIONS call to /w/ over and over again for about 1 minute. Then it stops and works fine for a while. I think it is some sort of a cron call, but I can't figure out why. Anyone have ideas where to start? It's causing my server to hang on a regular basis.