So for some strange reason, (could be b/c I was installing things for conky?), after a reboot (left the suspend|hibernate|reboot|shutdown popup over 60sec so it shutdown automatically >_<;) metacity didn't start and I had to do a manual startup. So if you're in this situation then you've come to the right place. I went thru hoops to find it but here is a link to the bug report and yes I know it's for Ubuntu but it did solve my issue. https://bugs.launchpad.net/ubuntu/+source/metacity/+bug/550082
For some reason or another, something put in "Hidden = true" into my ~/.local/share/applications/metacity.desktop and that screwed up metacity's loading.
so instead of deleting the whole file, just delete that one line.
reboot and you should see your window borders again ;)