Firefox to Blame: Backslashes in Comments

In comments, I was receiving backslashes in front of quotation marks and apostrophes, but I could not replicate them myself on Windows or Mac with a slew of browsers. After asking the users that were commenting and making backslashes about their OS and browser versions, I figured out that it was old versions of Firefox. Somewhere between version 1.5.0 and 1.5.0.7 (not positive), were creating the problem. I know 1.5.0.7 does not create the problem. Anyway, after upgrades to 2.0 the users no longer create the backslashes in comments. Can anyone explain this? My site is a small, personal site, and I know most of the readers, but I obviously can’t control the browser of everyone out there. Anyone have any ideas?