Scoreboard Resetting

I am finding an awful glitch, (while using a command block scoreboard system as a virtual currency on my sever), where if I fall to the ground, my score is reset.

I use the kills variable to keep track of currency, and it also gives you a $1 with every kill. But if you fall to the ground from any height worthy of damage and the "fall sound", it resets my score.

What is happening?