You could be a lifesaver here! ... you mention that username and password are not necessarily required. I left it blank but when connecting it keeps popping back up and asking me for these.
I was previously using my 8703 with Voyageur and I went and looked at those settings and had the following:
Mobile Number: 416xxxxxxx
Original Voice-Mail Password: yyyy
Get IP Address Automatically = yes
Get Domain Name Service Automatically = yes
I've tried these things in the username and password but nothing seems to work. Any thoughts anyone?