Well, the tyre pressure monitor works OK. I rode the bike up and down the lane tonight after washing yesterdays salt off and got a red master warning light and the RDC was flashing telling me I'd dumped 1 bar of pressure from the back wheel.
Looks like I'll need a new tyre and there probably isn't any in the country yet.
Exactly the same thing happened to me 2 years ago on my K16 on exactly the same road I was on yesterday. That turned out to be 2 inches of welding rod through the back tyre, not spotted the problem on the GS yet.
Future..on order-BMW GSA LC,
Present..BMW R1200GS LC, K1200R-SPORT, R1200S,HP4
Past.. BMW R1150GSA,R1200GSA,R1200GS,R1200RT,K1600GT