Burst posting means that you posting a lot of (low quality posts) or (off topic in threads) in a short time  !
If you doing that only to increase your activity or post count to maybe rank up it can be seen as burst posting too.
Bots have done that too in the past to keep the threads on top of the page where they posting.

Also maybe its possible because of your Username or a other reason!

But you have to wait for a Moderator or Global Moderator to tell you what exactly the reason for the ban.