Installed fine on ebay.co.uk, shows up listings very clearly. Top work!
Great script. Love the concept. Makes items that have been bidded on stand out fantastically.
Only one bit of critisism for you..
// @name eBay - Hilight Items With Bids
// @namespace http://userscripts.org/users/126140
// @include http://*.ebay.com/*
As there is many extensions for ebay, you should change the "@include" to.. "http://*ebay.*/*"