The reason you have to scroll to the right is the manner in which your signature image is not showing up, if that makes any sense. You are showing the URL for the image instead of the image and the URL is long enough to go off the screen to the right. It happens occasionally when somebody posts an extremely long URL. The program won't break a URL unless it arrives at the very right hand margin and only then will it return to the next line. for some reason it is showing up without scrolling on this thread so maybe there is something else not in order. I checked your "signature" thread and it does scroll there.
Try either getting your signature image to show up by correcting something that is either missing or misspelled in the address or try removing it temporarily and see if that doesn't resolve the problem.
OK, I checked again and it ISN'T the URL that YOU have posted, it is the URL that is posted on one of RON'S posts in your "signature" thread. About half way down he starts out with "How's this?" and there is a blue URL in that post. THAT is the culprit.
BTW, the reason your image isn't showing up is you missed the tail end of that URL when you copied it off of Ron's post. There is a "/purpleO.jpg" on the end that isn't showing up in the address at the bottom of your posts.