2007 Cayenne - strange power steering issueh

[sgrimshaw]

Got a strange problem with the power steering on my Cayenne S.

Sometimes, when I start the car my steering is really heavy.

If I immediately shutdown and restart the engine the steering is then fine.

If I don't switch the engine off and restart it, then the steering will be heavy until I do.

Any ideas?

[sgrimshaw]

Still not found the problem.