"An error occurred while contacting the Apple Online Store. Please try again."

I have the same issue 10.7.4 OS and iPhoto 11 version 9.2.3

Same problem here, reproduced on 2 different Macs on two different internet connections. The store is down!

I am having the same problem. How are we going to get this fixed? Seems like a lot of people are not able to buy their books

I have had the same problem. I read every post on this and many other websites. Nothing worked. I decided to try upgrading to Mountain Lion and noted while trying to do this that I could not connect to the App Store. I could sign in and use iTunes fine but not the App Store. I searched and found the following site to fix this problem: http://b.rthr.me/wp/?p=356. I followed the instructions which took about 5 minutes. After restarting as instructed I could now connect to the App Store. It also solved my problem in iBook and I am now able to purchase by book without any problems. Good Luck! It saved me and Christmas this year!

Here's what worked for me: in iPhoto Preferences > Advanced, select another country for your Apple store. Wait for it to turn from grey to black, then select your home country again. It seems to reset the connection somehow.