In the USA

My brother's Nokia N800 works nicely with T-Mobile using his Treo 680 about 20% of the time when we try to connect. No idea as to what the problem is.

I have tried to configure my Nokia N810 to work with T-Mobile using a T-Mobile Dash and a Blackberry Curve 8320. I was unsuccessful.

I have searched this and other websites for information on proper setting. None worked for me.

If someone has a working T-Mobile USA connection using either of these phones, I would appreciate learning your exact settings.

Also if another phone works well with T-Mobile and the N810, I would appreciate the recommendation and the settings.