AB's server automatically detects duplicate posts and removes them. If you've been around here for a while, you'll know that AB can sometimes be very, very, very sloooooooow. You might click the 'Submit' button and nothing seems to happen, so you click it again. When you next check your profile you'll find that your 'removed' count has gone up by one. That's because AB received your answer twice and automatically removed the duplicate.
When I first had a couple of answers shown as 'removed' I spent ages trying to find out what they were. It was only later, when AB's server was going through a particularly 'sticky' time, that I worked out what was happening.
Unless you're in the habit of sending offensive posts (which I'm sure you're not!), your 'removed' posts will simply be the result of clicking the 'Submit' button twice and nothing to worry about.
Chris