I've had no voice/data/GPS problems with the upgrade to CE ROM dcd 2.3.0/2.3.1 KITCHEN and RADIO ROM 3.27.00
One thing I have noticed with some older/other CE ROMS is username and password are required. What happens is the phone dials #777 over and over.
Set username/password
1. START-> SETTINGS-> CONNECTIONS-> CONNECTIONS-> TASK-> Manage existing connections
2. Edit CDMA1X #777
3. NEXT-> NEXT until username/password
4. username:
areacodetelephonenumber@mb.telusmobility.com (ie
1235550987@mb.telusmobility.com)
5. password: esndec (ie the number on the phone under the battery)
Going to WM6.1
1. Hard-SPL-240-MFG.exe
2. Titan_Radio_3.27.00.exe
3. Run dcd 2.3.1 Kitchen
4. Wait 5min
5. Dial *22803
6. 1 for english / 2 for french
7. 1 for MSID MDN AKEY all that stuff
8. Wait 5min
9. Dial *22803
10. 1 for english / 2 for french
11. 2 for
Going to Original Rom
1. Titan_Relocker.exe (this restores original bootloader)
2. Telus_HTC_P4000_WM6_07252007.exe
3. Wait 5min
4. Dial *22803
5. 1 for english / 2 for french
6. 1 for MSID MDN AKEY all that stuff
7. Wait 5min
8. Dial *22803
9. 1 for english / 2 for french
10. 2 for PRL (preferred roaming list)