Adding a scroll bar on the submit / edit page

Another request:
I use a 3 column design website.
When users want to add an image, the template is too wide and covers the right column.
I think perhaps Drupal 5 was conceived for 2 columns because the same problem appears with the Theme edit page.
One soution I saw was with the upload preview module which inserted a horizontal scroll bar on the submit page which solves the problem :)
Many Thanks,
Drupalworld