I am pretty sure I had more that 50 post, when I log onto post after 2 weeks later my post count was only 26.
Keep in mind that you only receive 1 post credit for posting on "Introductions".Starting from your 2nd post on that forum you will receive no credits.Also I'm not 100% sure of this but they may be a length criteria.In other words if one were to post something like...."I agree" that may not be long enough to qualify as a true post and may not count.I am not sure about that,but there is a member on here that does this and her count doesn't ever seem to go up. All in all based on my observations,DP appears to be pretty well glitch free.
When I first joined, I had read and answered in a genuine manner -- I think posted a few on those sentences thanking the OP. Perhaps, as you suggested, I should put better effort when responding.
Maybe it was your other account that had more posts. Give us a link to one of your posts there and we can check it out and see if there is a problem.