Had interesting situation. Installed WP e-Commerce Grid View on test WP e-Commerce site because it looks quite good. All went well, until I noticed that on the main machine I was testing the finished pages on was not showing items which were added after clicking on 'Checkout'.
Again - Add a product either from the grid, the product page or the latest products widget - all added ok to the shopping cart. it was only when going to 'Checkout' that they would disappear.
This was in Google Chrome ver 32.0.1700.76 m (latest at time). Some testing with other browsers (Internet Explorer 11 & FireFox 26.0 didnt show the problem.
First off I thought it might have been Win 8.1, as had first off tried with the dev computer which had Win 7 and all worked. I happened to have a few others around so started comparing. Closes was a Win 8.1 with previous version Chrome 31.0.1650.63m - it worked ok. While I was testing Chrome snuck in an update to 32.0.1700.76 m (which was a bit annoying - hard to do good testing when that kind of thing happens).
Eventually thought it was worth trying to clear the Cache on Chrome (also did a reboot - if you can call it that in Win 8.1).
This did the magic trick and all working - it shows the products in the shopping card at checkout.
(P.S. I rarely post - not too many exiting things happen like this, I hope it might helps someone else ease their day!)
Great plugin guys! Really makes the shopping basket seem much nicer.