I dont think that I have posted 150+ points worth of posts in the last few days, I could be wrong, but do you recieve more than 5 points for posting a reply in the forums?
Maybe you have posted that much and you just didn't realise, its easy to post more than you think. It happens to me all the time, I look at my points and think, jesus, I don't remember posting that much yesterday or whatever, so yeah, maybe you did actually post that much....or maybe someone donated you points?