I have had my pearl (8100) and curve (8310), both on t-mobile working just fine. The one caveat is that I am using os 4.5. Using earlier OS's on the pearl gave me nothing but problems. OS 4.5 is becoming quite available. Just search around, several cell companies have officially released it for several different phones.

I then followed the instructions in the first post of this thread.

http://www.internettablettalk.com/fo...ighlight=pearl

Tethering now works very reliably for me.