After much head scratching I finally worked it out!
On my previous build I had the preview tab (Windows 7 "peek" thingy) working in Chrome, but couldn't remeber how I did it, well, after much searching I found it here: http://www.google.com/support/forum/p/Chrome/thread?tid=607ed61598ba1510&hl=en
Basically, add the following to the application shortcut:
This sorting things out and normality was restored...
This post is as much for my own future reference as it is to help others!!