My old housemate had a similar experience on one of the games on the lottery website. "Eeee look at this I've won shitloads" *small pause" "Aww nar fuck it, it's all gone".
Aye, I'm down to £16 from £62 now, but still. I withdrew £100 with no stake, nice one.
I think my highest after I withdrew £100 was about £81 and now I'm down to 22p.
But still I'm impressed I had the restraint to withdraw anything at all.