Dolichos Lablab or Hyacinth Bean

I've tried many times to get Dolichos Lablab going, they look so appealing in the pictures, but have had absolutely no joy. I'm not sure I've ever been able to germinate one, let alone get one to flowering. I sowed a tray a week ago, took no chances, no extra water, in the propagator, and b*** me, they still rotted off within days.

The final seeds in the packet have been placed on a slightly damp tissue in the kitchen. They've absorbed water, now i'm waiting with bated breath to see what happens.

I bought the seeds last year - do you think that's fresh enough? Any tips or hints?