Apologies for the cross posting here from http://www.magentocommerce.com/boards/viewthread/23325/P15/#t214481 but it just dawned on me that this is actually most likely version related.
I installed a new clean install of Magento Version 188.8.131.52 and the sample data and added in the Google Analytics tracking code in the System -> Configuration - Google API -> Google Analytics Account Number.
Upon completion of an order the success page (index.php/checkout/onepage/success/) does successfully show the Google Analytics page view tracking but does *not* show the ecommerce transaction tracking.
Looking into this a little bit further I looked at Ga.php (/app/code/core/Mage/GoogleAnalytics/Block) where the Analytics code gets written. It does (of course) have the full code to add the transactions for ecommerce tracking but they aren’t getting added to the return call for some reason. It appears (from what I can tell) that $this->getQuote(); in the getQuoteOrdersHtml() function is returning null.
As I say this is a totally new clean simple install and from everything I have read the ecommerce tracking is getting added automatically for many of you (however not for others I suspect).
Any thoughts, suggestions and/or ideas (or even verification that the same is happening for others) would be appreciated.
Note I did see an article which was relating to the JS and Analytics not returning correctly but I don’t think this is pertinent as it isn’t even getting as far as inserting it onto the page. http://www.magentocommerce.com/boards/viewthread/77774/