Q: App Store "Purchased" tab freezing.  Can't download redeemed things!

I'm trying to update my OS X 10.6 Snow Leopard to 10.7 Lion and then 10.8 Mountain Lion.  I redeemed both the OSs and my purchace screen on the App Store keeps flashing.  My items won't download and when they start downloading, they freeze up.  Help!!!  I need to get this done ASAP and this is extremely frustrating!  I've tried as much as I can on my own and any help would be great...