Whilst driving back from picking up my partner today, there was a point where we got to a give way T-junction going up what was a pretty steep slope.
I stopped us at the top, put the handbrake on to wait for a gap in the traffic, and then was somewhat alarmed to find that the car was starting to roll backwards! I managed to pull another "click" on the handbrake, but it still didn't stop us moving entirely.
Fortunately I managed to cover the foot brake, then effectively do a bit of heel-and-toe so I could keep the clutch at the bite point and get us out without the car rolling back again, but I'm going to give the Dealer a call tomorrow, because I'm pretty sure that's not supposed to happen...