Scoreboard can have UUID instead of player name

I have a scoreboard on my map where i use the WalkedOneCm criteria.

i have been detecting this in the sidebar and after updating to 14w05b the name:
b9f731fe-ead3-4c5c-863e-da9d35e18309 appeared in the scoreboard.
the name comes up when listing all the players in the scoreboard, but it does not appear in any other objectives.

It does not disappear even after using the /scoreboard players reset b9f731fe-ead3-4c5c-863e-da9d35e18309
only my score does

the map was originally used on a server, but i have used the /scoreboard players reset... every stored player since moving it to singleplayer.

map was made in 1.7.2 and was just updated from 14w04b to 05b

I do not know how to reproduce this