As best I can tell, it looks like you redesigned the forum since my last visit, making the page narrower.
The forum now fits nicely within my browser window, and horizontal scrolling is no longer required. Yea! Not sure this was ever a problem for anyone but me, but now it's not a problem for me either.
Please enter this note in your "Goofy Post Of The Week" contest. I want to win one of those caps with the propellers on top!
And thanks again.