Have just spent a frustrating hour trying to tether my mac via os x and windows xp under parallels to telecom XT network using a new Telecom R6.

Thought I'd pass on the fix to stop others wasting their time..

Neither worked - it appears some muppet has shipped the JoinME software with internet.telecom.com.nz as the default APN

To fix on Windows:
Start JoinME
Select settings from the Tools Menu
Click the Modem setting tab
Change the APN field to: internet.telecom.co.nz
Click OK button.
You should now be able to connect

To fix on Mac:
Start JoinME
Click Internet Button at top of screen
Select Edit Configuration from Default Configuration popup
Click the + button to add a new one (you can’t change the existing one)
Select the newly added configuration and click the edit button
Set the Telephone number to *99#
Click the Use the Following APN name radio button
Enter internet.telecom.co.nz in the field below
Click OK
Click Close
Select your new configuration from Default Cofiguration menu.
You should now be able to connect.

Cheers,
Julian.