I used the VQMod from Simon at UKSB, but it stopped working and for weeks I've driven myself potty trying to work out why, much to the frustration of Simon I guess who couldn't understand why it wouldn't work for me. I did email/bug him quite a bit about it. Sorry Simon! (his Google mod is the d's b's btw)
This all coincided with installing another Mod, and doing some other hacking.
This morning the light bulb went on! I had edited, and therefore copied to my theme folder, some tpl files. Thsi meant that the path use by uksb_grid_view_default.xml was no longer valid as it only references the default theme tpl files, and now OC wasn't using them anymore. DUH!

So if anyone else ever pulls their hair out then hopefully they'll come across this post. I know this is OC 101 but we aren't all perfect

Look for this path in the xml catalog/view/theme/YOURTHEMENAME/template/product/ and update it with your theme name. 4 occurrences.