They wrote a thread over at Hivewire saying the points system is messed up (supposedly this happens after every new year). Lisa, one of the admins, was able to fix it the last time around, but since she's in the hospital and there's only a few days left, they decided to just shut the points off.
Other than that, it also depends on the size of your order. i.e., you can't spend 1500 points on a $15 item and get it for free. I thought I read somewhere that it can only count up to a 15% discount at max. I could be wrong on the amount.