I saw the same problem on cm-10.1.3-RC2-ovation: "wallpaper quick render" enabled causes bootup to stall on the animated logo. Clearing cache was the only way to complete with it enabled. Disabling restores the ability to boot and reboot normally.
It's a devious bug as you might only run into it days after enabling the feature. In my case, it was a few days after a fresh CM installation, having setup and installed everything the way I wanted. adb logcat didn't show anything obvious within the boot loop. I spent a while building the installation back from scratch with incremental nandroid backups attempting to find the point where things broke. Glad I found this thread instead!
It'd be nice to have it fixed as quick render makes scrolling between home pages noticeably smoother.