Works for me, although I'm no longer now logging into MSN as a matter of course, instead focussing more on gtalk /skype / facebook (in that order). There's a limit.!

If you can't connect via 3G it's more likely to be a carrier/tariff issue. Some providers prevent use of voip/IM on certain tariffs. Other's have this in T&C but don't enforce.

I've stayed with 3Uk, one of the big reasons being that ever since they launched their first decent data tariff (xseries) about 3 years ago, there's been no blocking/restrictions & a decent (for 5 UKP pcm) 1Gb fair use policy (rumour is hard cap is at 2Gb)