Gracias a los chicos de xda mi tema se ha resuelto. Solo hay que hacer unos pequeños cambios en el registro:
La HD2 no incorpora en el registo el DWORD COD, así que hay que crearlo:
Change Registry setting:
HKEY_LOCAL_MACHINE\Software\Microsoft\Bluetooth\Sy s
Add the DWORD setting name COD and value 5374476
This makes devices see the HD2 as a 'Normal' phone.
Then I made the following registry changes:
1. Modify the HandsFree plug-in: HKLM\Software\WIDCOMM\Plugin\HandsFree
i. Change SupportedFeatures to 45 (default is 1135 mine was 1379)
ii. Add value HFBDA binary, set to same value as LastConnectedBda
iii. Add value HFDeviceType DWORD 2
2. Modify the WIDCOMM bluetooth general settings: HKLM\Software\WIDCOMM\BtConfig\General
i. Change bdaddr to (no value) delete the existing key value
ii. Change DisableReopenAudio to 0 (default is 1) I didn't have this registry key so I created it with DWORD value 0
3. Reboot device
Seguro que a quien tenga el mismo problema tambien le sirven