The problem appears to be caused by a very! very! very! long string of spaces codes "&nbps;" inserted directly after the text string "Thanks for dropping by and have a great day! </font> ---long string is here---- </p></font>" in the description. Removing the string of spaces brought the text back to normal width and a correct wrap as interpreted by IE7. See if this displays correctly in your IE7 and Firefox before you make the change at eBay. Here's a practiceboard without those spaces:
http://www.practiceboard.com/?9239901
Use Revise listing with description in HTML mode to locate and remove the spaces codes, then test with Preview before saving.
Danno