epb problem on steep hill

[jpm72]

I'm very new to Passats. (1.9 tdi manual 2006) I've only had it for 2 weeks and found it fine - handbrake comes off automatically when driving off even on a moderatley steep hill. BUT on a really steep hill it refuses to release, eventually after much dippling of clutch, hitting of EPB button, reveving of engine - it does release, fortunately before I've burnt out the clutch ! I've read through many posts but can't find any reference to this problem. I've read that the control unit contains an attitude sensor, is this where the problem exists?