It would also be interesting to gather the radio log while trying to call the phone. Please try this:
adb shell sudo /system/bin/logcat -b radio -c sudo /system/bin/logcat -b radio > /tmp/radio.txt
* Now try to call the phone. After it fails:
exit adb pull /tmp/radio.txt /tmp/
and attach /tmp/radio.txt to the bug.
It would also be interesting to gather the radio log while trying to call the phone. Please try this:
adb shell
sudo /system/bin/logcat -b radio -c
sudo /system/bin/logcat -b radio > /tmp/radio.txt
* Now try to call the phone. After it fails:
exit
adb pull /tmp/radio.txt /tmp/
and attach /tmp/radio.txt to the bug.