Google.co.uk ranking UK sites differently

[BigB]

On some searches google.co.uk is now bumping some, but not all, UK sites up to the top of the SERPS. This is the "all the web" search, not the "pages from the UK" search. For the searches affected, google.co.uk "all the web" results now differ from google.com results. But unlike the "pages from the UK" search, it is more than just a .uk domain or UK IP address that is needed to get a boost.

Who's winning and who's losing?

[Dynamoo]

At the moment it's only the results from google.co.uk propping up one of my sites.. the SERPs for "UK only" are definitely not compatible with the "entire web" search. Very odd. Not complaining though.