I'm running the latest version of firefox, but for the last 3 days or so, it has not been loading pages properlly, and they come out in text outline only- see pic:

Our wireless router has been doing weird things recently and not sending a internet signal to my laptop sometimes (I have to go upstairs and reset it and it fixes itself immediatly), not sure if other wireless things in the house are interferring or not. Don't know if that is related or not.
Internet Explorer and Google Chrome still work fine, as with Safari on my iPhone, although Firefox was my favourite and I'd be keen to here any tips or fixes someone out there may know.
Thanks in advance!