We signed up for on-line billing from our utility company; when I log into their website and click onto the link to "view my bill" Firefox opens a new tab, but nothing loads on the screen; the "address" bar near the top of the screen where you'd usually see the url for the tab reads simply "About:blank" . I have the same issue with messages received from our bank, which are usually sent as .pdf files. I frequently open .pdf files from other sites without any problems, so my copy of Adobe Reader seems to be working okay.

Any suggestions greatly appreciated.