Your car does not have a camshaft position sensor.
That code is for the crankshaft position sensor, G28.
http://wiki.ross-tech.com/wiki/index.php/16705/P0321/000801
The Ross-Tech document mentions a TSI 2007067 regarding electromagnetic interference. I have not found a copy of this TSI.
I have found bad wiring issues on the crank sensor causing problems. Replacing the sensor or repairing the wiring pigtail on the crank sensor fixed it. Rarely the sensor wheel inside the crankcase comes loose.
From the tech brief on this engine:
Engine speed as determined by G28
The engine speed is one of the main factors which the
control unit processes in order to calculate the injection
quantity.
Substitute function
If the engine speed sender is faulty, an emergency running
program is activated. The needle lift sender G80
supplies a substitute engine speed signal for this purpose.
The injection quantity is reduced, the commencement of
fuel injection is controlled and the charge pressure control
is switched off during emergency operation.
If the substitute engine speed signal of G80 fails as well,
the engine is turned off.
I would expect severe performance reduction is in this limp home emergency running mode.
There are also posts that indicate you can get this code due to fuel delivery problems. It is not clear, but these posts may have been for a PD engine. By the way, a BEW PD will not run with this sensor unplugged, but a BRM PD engine will (this is of no import to your engine - just a note for future searchers.)
If the engine has fuel delivery issues then unplugging the crank sensor will obviously not help.