In about:config.Are these your settings as provided by this LINK
mousewheel.withnokey.sysnumlines = true
mousewheel.withnokey.numlines = 1
mousewheel.withnokey.action = 0
Until recently, I've been able to scroll within web pages using the mouse's center scroll wheel with all the browsers I use (FF, IE, Opera). For some reason I can no longer do so in Firefox. I tried the overkill method and uninstalled FF via Add/Remove Programs and deleted the Mozilla Firefox folder from the Programs directory. I haven't made any changes in about:config since I've reinstalled, but the scroll wheel still doesn't work! I even tried with Scroll Lock on and off; no difference. Scrolling with the center wheel works fine in the other browsers. Did I do something stupid, not related to the browser settings?
I'm using Windows XP Pro and Firefox 18.104.22.168 on a Dell Inspiron 9200 with a Dell M-UVDEL1 mouse (a very vanilla setup).