UK sites disappeared from MSN.com a long time ago, and I've been using MSN.co.uk exclusively to check listings since then.
Apart from anything else, this means one more place to monitor and report on :-(
Anyway why would you be upset about having your site apear in another set of results!? I would would love it if mine apeared in the UK results...and the rest intead of just the .com
It's still really hard to get a good position on .com for sites hosted elsewhere, somewhat easier on co.uk
But it might have happened earlier.