After following ch1ptune's guide to installing sabnzbd. I managed to get all three running on my WDTV-Live on 0.5.1.1 (based on 1.05.04)
After installing sabnzbd to get all the proper dependencies (must install python 2.6 and py26-cheetah) and ran sabnzbd once to get the .ini file , i copied sabnzbd's files onto my usb drive where i also unpacked sickbeard and couchpotato (I just like them there).
After trying to run sickbeard and getting the segmentation fault error,
I had to rename /opt/lib/python2.6/lib-dynload/_locale.so to get it to run.
Couchpotato didn't give me any problems after this.
However, I have been having alot of problems getting a startup script to run. Trying everything I've seen work for other people (SxxSabnzbd scripts in /opt/etc/init.d, S99user-script, etc.) I can't even get the scripts to execute after chmod'ing them and whatnot. Anyways, I thought I'd share, and I'll be back later/tomorrow with some more questions if I can't get the startup scripts going.
Also: sickbeard's sabtosickbeard script wasn't working even after i changed the location of python in the script.