some web pages are smaller than the screen and the text is overlapped
some web pages load smaller than others to the size of the screen, when that happens the text on these pages are cramped and overlapped and are not readable.
URL of affected sites
http://http://www.officedepot.com/customerservice/customerServiceSet.do
Opaite Mbohovái (1)
Reset the page zoom on websites that look wrong: "View > Zoom > Reset" ( Ctrl + 0 (zero)) See http://kb.mozillazine.org/Zoom_text_of_web_pages
See Font size and zoom - increase the size of web pages and Font size and zoom - increase the size of web pages and Change the fonts and colors websites use .......... If you increased the minimum font size then try a lower setting (default is none) as a too high value can cause issues like you described. Tools > Options > Content : Fonts & Colors: Advanced > Minimum Font Size Tools > Options > Content : Fonts & Colors: Advanced > "Allow pages to choose their own fonts, instead of my selections above"