"No Dial-Up Networking
In a related story, Engadget is reporting that the Cingular has disabled Bluetooth Dial-Up Networking (DUN) on this device.
If this information is correct, then the Cingular version of the Treo 650 will lack the ability to act as a wireless modem for other devices, like laptops.
Sprint also disabled DUN on its version of the Treo 650, but says that this is because the software required was buggy. Sprint intends to release a patch that will re-enable DUN on its version of the smartphone. "
-> http://www.brighthand.com/article/Treo_650_for_Cingular_May_Be_Delayed
And many other services are disabling this. What happens are people like you try for weeks or months and create lots of support calls (some pay money!) and only discover that it doesn't work until later.
Bottom line. Take the devices to your cell provider service counter and have them make it work. Doesn't work? Seek new service.
Bob
Dear All,
I have recently purchased an HP iPAQ hx2110 and tried to log onto the internet through my GPRS-enabled Nokia 3650 but couldn't. I have tried HP tech support, went through their instructions step by step but I always get an error message (that the connecting modem has disconnected). I have also tried with my GSM provider Vodafone to get them to solve the problem but to no avail.
I really would very much appreciate it if anybody can provide any tips on the matter
Thanks

Chowhound
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