odd stall

1999 Pug 106 1.1 petrol. Has happened twice now that, pulling away after..the only thing I can think is 'slowing down' (once after bearing right at a roundabout and once turning right, without stopping, both in 2nd at about 15-20), there's a total loss of power no matter what I do with the throttle and the engine will, slowly, lose revs then stall. As soon as it does I can re-start and it runs fine again. It generally runs well but I'm a bit worried that it could happen when pulling out into traffic!

Any ideas? No idea when it was last serviced, only recently acquired it, 62k on the clock.

Chandy