You post a lot in General Chat - these posts do not count towards your post count total. You also have had a few posts removed from the Forums due to quality issues.
All posts must contain some meaningful and quality content to remain on the Forums - anything outside of this scope is deemed as Fluff posting - these posts are in turn then removed from the Forums and therefore your post count will also decrease. Another point to note is that you're also a new member and you have to wait a total of 90 days to expire before you can avail of the signature option. You should also note that signature links are nofollow :agree:
Guidelines you should familiarise yourself with: