When I say that it's a known issue that backup/restore in broken in the newest CWM, I say that because a number of other people on these forums and on RootzWiki have stated that they've had issues too with backup/restore.
I based it on this process...
1 person has issues, ok; maybe something just went wrong.
2 people had the issue, alright.
3 people? Things are looking strange.
More than ten people having backup/restore issues? It's broken!
So yes, I think that backup/restore in broken in the newest CWM. Backup/restore is definitely working in the older 184.108.40.206 version.
Current Devices: Samsung Galaxy S4 and Nexus 7
Retired Devices: Verizon Samsung Galaxy Nexus and Samsung Droid Charge