I have just installed the latest version of Flash (11.7.700.169) and I am running Mac OS 10.8.3 (64-bit) on a 2012 MacBook Pro. The CBC.ca website says this is a problem between Apple and Adobe (http://www.cbc.ca/player/help.html#T08b) says:
"There is a known compatibility issue between some Mac video hardware and some versions of Adobe player. This manifests itself in an inability for the hardware to properly process live video streams. Unfortunately this problem is out of our hands and will only go away when Adobe and/or Mac invests in a fix. We suggest updating your Flash Player and/or browser version frequently to take advantage of any fix that may come through the pipe. (see Minimum System Requirements)."
This is Canada's national network. Surely someone can fis this soon!