Has anyone had this problem or is it just me?; Going from RC2 to the new Beta I get this at boot and then freeze;

PANIC: VFS: Unable to mount root fs on unknown-block(179,2)

I've tried three different SD cards and even gone back to RC2 which still works great. Also tried linux and windows image creation tools. No luck.
I really want to be able to try the Beta with its auto mount NAS over wireless and USB audio fixes! Best use for a Pi ever!
Cheers!

I downloaded the beta on a Mac, but used both win and Ubuntu platforms to write the card. I will download the image again as suggested and post results!