Does android switch to a different APN when in hotspot mode?

I've tried turning on the portable hot-spot mode on my nexus-one and got a message from my operator saying that my plan doesn't cover data traffic made through the web.operator.com APN, as opposed to mobile.operator.com (my "usual" APN). That made me curious. Does that mean that android switches APNs when the hot-spot feature is active? And if so, is this a built-in feature/configuration option or an operator customization? **Update** No, the phone doesn't switch to a different APN, but I'm still not sure what triggered the message from my operator... **Update** There's kind of a persistent rumor that European Nexus-One phones get tweaked OSes, see the xda-developers forum threads [](http://forum.xda-developers.com/showthread.php?t=714747&highlight=vodafone) and [](http://forum.xda-developers.com/showthread.php?t=709449&highlight=vodafone) , or google nexus-one forums [](http://www.google.com/support/forum/p/android/thread?tid=7fd03026a89e3568&hl=en) and [](http://www.google.com/support/forum/p/android/thread?tid=71fe16740c60ebf0&hl=en) . One of the most likely tweaks seems to be the tagging of hotspot traffic, in order to be able to charge for it differently.