I have been playing around with text size in Firefox since my eye surgery in case I should have problems in the future. I increase the minimum font size to 15 because the default is so tiny. I noticed when I went to the Windows page on Softpedia the text overlapped really bad. By chance I installed Adblock Plus, I normally just put up with the ads but I have read so many good posts about it I wanted to see what it could do. Anyway, when I went to the page with the overlapping text with Adblock Plus the text looked 100% better and was readable! The Linux page displayed fine with or without the add-on.
I know I am not the only member here that uses bi-focals, so if you are having this problem with text give this a try.