This just started happening.
It may be that someone sent you a huge picture on your pings. Scroll all the way down and take a look. It basically moves your margins to the far right. If that is the case, post like mad and get it to the next page then your pings will go back to normal.
It’s happened to me.
I hope this helps.
Did someone post a huge graphic to you in the past couple of days? The browser window will widen to the size of the graphic. Until that moves off your my comments page you'll have that effect. In the meantime you can click on "brief" at the top right hand side of the page and you'll only see who sent you the ping, not what they said.