Google Ecommerce Analytics Repair

I have Google analytics ecommerce code on a thank you page of a wordpress blog. It has run perfectly well for 2 years, then in August 2010 my Google analytics ecommerce conversions flatlined. The script is now broken despite not editing the page. I assume a plugin update has broken the code, or some other plugin update (not a wordpress update). The task is to fix the code from a txt file of the html that I will provide. I get 20 transactions a day, so it won't take long to see if the code is repaired. If it still won't work, then the wordpress blog or the plugins may need troubleshooting.