Try flashing the newer 188.8.131.52 CWM. I also had that black screen problem occasionally with 184.108.40.206 and I think other people did as well. FYI, I was able to get to recovery eventually if I kept rebooting. Sometimes it works on the first try, sometimes it doesn't.
But I flashed the TWRP 220.127.116.11 image that dhacker posted last night and I haven't gotten any black screens yet, even after booting into recovery several times just to test it.
Device: Motorola Droid RAZR HD xt926 | Bootloader Unlocked & Rooted | Recovery: TWRP 18.104.22.168 | ROM: CM11 nightlies