Hello, i have the same problem. after clicking add to cart the site shows a blank page. It does contain html in the source but it doesn't show it.
I grabbed a line from the log file:
[Thu Mar 25 14:04:41 2010] [error] [client 87.212.38.171] File does not exist: /home/metierab/domains/learningdevelopment.nl/public_html/joomla/SpryAssets, referer:
www.learningdevelopment.nl/joomla/index....tuemart&Itemid=5
The weird thing is it is asking for SpryAssets. I placed a folder with spryAssetst (all possible js files) in the root but it didn't fix the problem. I think this is a wild goose chase but still needed to mention it.
Can the problem be caused by the placement of the ga code (above body instead of at the end?)