Thought I'd post this as it stumped me for nearly 2 hours until I sorted it out. After uploading the columnar layout grid for product listing I found that the background image I had set for the css button I had created for Add to Cart did not appear in IE but was working perfectly in Firefox. It had been ok in IE before so I looked at the new templates I had installed but couldn't find that it changed anything. I hadn't changed the css button stylesheet either.

I then fiddled about with the css button and found that when I added a color to the button, lo and behold, the image reappeared! I guess this is yet another quirk of IE but still I don't understand why it was ok before, but I had to make this adjustment to get it to work ok after the upload. Anyhow, in case there is someone else out there similarly going mad on this, hope it helped.

If anyone can help get the product listings to line up in the columnar grid in Firefox, (they're fine in IE), it would be appreciated.