When you kill 25 drone I bots, you are told that from now on, you will only get a bonus when you kill drone II bots, and from that point on, the game does not count your Drone I kills towards your bonuses (i.e. if you kill drone I, it does not update the count towards the next bonus). The problem with the way it is implemented right now is that if at that point you keep killing Drone I bots, each kill counts as the 25th and gives you the 400/125/125XP bonus. If you kill a drone II, the game picks up the count correctly again, but I suspect that the same happens if you get to 5/10/15... drone II kills and then keep killing drone I bots to stay at the multiple of 5. Unfortunately, I did not test that because I got tired of chasing Drone IIs in a bus.

Yep.. i have got that too.. (two days ago?)

just bumped in case :)