mine is abit like that doesnt always work but i think its the battery just havnt got round to replacing it!
 
You can alter it in vag com to unlock just the drivers door on 1 press or 2 presses unlocks all the doors.

As been said before a 3 button remote can operate the boot alone.
 
Had this problem at the start of the year. It just stopped working one day.

Fixed it by just disconnecting the Car battery for 15/20 minutes and then hey presto it was fine again.