Old thread, but my car has just started doing this.
It's most likely the same known sensor / rack fault my car has.
Basically try replacing the sensor, but you might need a new rack also....plus they recommend a 'part modified wiring loom' I am yet to find out if this is literally just wiring, or includes the sensor also...
I will update the thread...
the bad news is the rack and loom are ~£1k, no joke!
