After a lengthy discussion with BFG the suggestion was to delete & re-install the game..which I did. When I used my name from the 1st. install I found myself back @ the same spot I had re-started previously..where it kept telling me I had already used those codes for the tower..so..I put in a new name & the game went thru to the end without a hitch!! Got to save Venice & had fireworks for a reward...tough game..but love it! Got to a score of 1,111,598 when I wiped out & had to start score over...went to see what would happen if I tried a new game with the same name & there it wants to know if I want to override my previous high score..my guess is the game didn't install properly the 1st. go round & when I got to level 51 it took it to be the end of the game & wanted me to override my score & start over..mind only a guess on my part, but hope it helps someone.