I recently enabled Google Checkout on my Zen Cart store and have noticed a sharp decline in the number of orders I'm receiving. After clicking around a bit I noticed the shopping cart page was dreadfully slow (taking greater than 30 seconds to load in some cases). In an effort to find out what was going on I enabled "Display The Page Parse Time" through the Admin and this is what I found:

Without Google Payment Module Enabled:
Cart Parse Time: 3.356 - Number of Queries: 752 - Query Time: 2.56181386963

With Google Payment Module Enabled:
Cart Parse Time: 6.119 - Number of Queries: 4845 - Query Time: 4.88683219766

The same product was added added to cart in the above test. The only difference was enabling and disabling Google Checkout through the Admin. Sometimes I'm seeing query times greater than 30 seconds! Without Google Checkout enabled the highest query time I've seen is 3.2 sec. Why is Google Checkout causing so many queries to be run? My products have lots of attributes but there's nothing I can do about that. I have sql caching to 'file' as well. Nothing has helped. Anybody else running into this issue? Anyway to speed Google Checkout up? Thanks.