command block doesnt check death players any more

im making a pvp game. and when loading the new snapshot i found out that the commandblock doesnt check for death players anymore

is this a bug? hope so. it breaks so many systems people use
like dropping addittional items when someone dies.

how to reproduce:
1 get a command block,comparator,and make a clock (on singleplayer)
2 link command block to clock
3 put comparator next to the command block
4 put the command "testfor @a"
5 notice comarator turns on
6 kill yourself in such way that you can see the comparator
7 notice it turns off as long as your death