Posting is now enabled with a minimum karma required of 20 - that is, you must have gotten at least 20 upvotes on your comments in order to publish a post. Or an adminstrator such as myself or Robin (by default you should bother me) can temporarily bless you with posting ability - in the long run this shouldn't happen much.
You currently get a karma point just for automatically upvoting your own comment. This is scheduled to be fixed, but it's low-priority.
I also tried manually upvoting my own post - just t see what would happen.
Never never do that.
======== More seriously - shouldn't you get Karma from people REPLYING to your comments? Lots of Karma - I mean: someone upvotes me - that's nice - but someone actually REPLIES to me - wo hoo!