Yeah. I've noticed this too. I've filed a bug report with our web team, and we'll try to get that fixed. In the meantime, a simple back button and re-click seems to clear it up. Sorry for the inconvenience!
This happened to me a few times also, including just now. Clicking back did work to return to the pirate boards. It usually happens when I click "message boards" on the bottom of the page to leave the entry I was reading and return to the boards home page. It's the link across from "back to top", and above the Pirate101 logo. I keep thinking I accidentally hit a Wizard101 link that must have been further down than I had showing on screen. Nice to know I'm not the only one with this issue, and Jack's working on getting it fixed.