I don't quite understand what you mean by loosing the coins. I played for the first time, got ~400 coins and died on the third level. I did not reach the train and had 0 coins in the shop. I started again and had my ~400 coins again so I didn't really loose them. :)
Thanks for the Finding the bugs that I probably would have found!! And what I meant is that the coin count you see at the bottom of the screen tells how much you will get on top of all the other coins you already had