iPhoto 9.2 update trouble

[rokey]

I can download the update just fine, then the Mac goes to a gray screen with a spinning bar.

The first time that I did this, it went for 30 minutes before I restarted manually. I'm on the second attempt now and approaching 30 minutes again.

 

[rokey]

Update:

So I did a fresh install of Lion on this Mac (MBA 13" base model, purchased 3 days ago). I'm logged into the Mac App Store and I go to Purchased. iPhoto is in the list and I click to install it. It goes through the almost entire download and then, "An Error Occurred" appears inplace of the download progress bar in the Purchased tab. A few moments later my screen goes Gray and 3/4 of the way down in the center I get the Spinning Bar. Now it's stuck here.

Any ideas???