Yeah, this is the second thing I've tried to do on my new Mac (I'm new to Mac) that hasn't worked. The first was Ikea's kitchen designer tool, and then when I logged into my Yahoo account (which I've had for 10 years) it told me that I could no longer use the new interface because I had a Mac.
Is stuff on the web going to start not supporting the Mac in the same way installable software often doesn't support Mac? If Yahoo moves to their new interface post-beta and doesn't fix Mac support, that's really gonna piss me off.