it could also be the fact that i'm using the same price feed as steembottracker (http://postpromoter.net/api/prices) .... it is more stable, but maybe there's a skew in the prices ... i don't really know the cause, but ppl have been using the bot for quite some time so i'm assuming they're making a profit in the long run :P
RE: My own bid based vote bot! Woohoo!