A colleague and I have both noticed in the last week that we are not receiving MMS messages on our iPhone 4S's as we have normally in the past.  Instead we are getting a txt directing us to the pxtworld site with a one-off password.

I've checked the apn lists here and elsewhere including vodafone.co.nz and they appear to be correct on both our phones.  My colleague's phone is a "new" (refurb we assume) that arrived today and he's just updated iOS to the latest.  Mine's up-to-date as well.

Has anyone else had or heard of this problem recently?  Any suggestions?

For the record:
APN: line.vodafone.com
MMSC: http://pxt.vodafone.net.nz/pxtsend
MMS Proxy: 172.030.038.009:8080
MMS Max message size: 308200

everything else is blank.