Bluetooth DUN

[babybug]

Without data plan on my Bell Diamond, I used to do internet surfing on my diamond by bluetooth connection with my blackberry (using the berry as a modem).
After flashing custom roms, initial pairng between 2 devices is fine, however, once it is connected, it automatically disconnect itself and it wont connect between 2 devices afterwards anymore.

I have tried to flash various roms: juicy, alrom and mighty. They all give me the same issues. I flashed back to Bell stock rom, it will be working fine again.

What causes this? Any help will be sincerely appreciated.