I second janszoon in the post above.

Just installed fMMS on T-Mo US. No changes to any of the default internet connection settings; set it to havoc. Everything worked flawlessly. While connected thru wifi, it opened the GPRS connection in parallel and closed it when done. Did the same when sending and receiving. The sharing plugin is so ingenious!

I know about it since it was launched but hesitated to install it.
Excellent work frals! Thanks!