I thought you gave me the curse of "Wet Paint".
I clicked on the chevron to the far right of "recent threads" and the box went blank. Clicking on the now inverted chevron didn't toggle me back to the original list of posts. With the other boxes clicking on the chevron opens or closes a box such as the list of recruits or drops down a list of choices. With "recent threads' it seems to toggle you to a blank screen.
Like you the situation persisted. I shut down IE but it was returned when I reopened IE. I looked in the my control panel but didn't find anyting that deal with that situation. Finally I closed IrishEnvy and went to Internet Options in Explorer. I deleted the temporary files, history, and cookies and upon reopening IrishEnvy had no problem.