Firefox has recently begun opening "New Tab" with a URL called about:blank. Since I've set up popup pages to open in tabs, the about:blank pages pop up in tabs. This happens every time I open FF; if I leave the browser open for several hours it will have several about:blank tabs opened. I've read that "about blank" popups have been associated with a virus or malware and that these tend to redirect users to other pages. However, I have run virus scans and spyware/malware scans and have come up empty and the about:blank popups don't redirect me anywhere else.

How can I stop about:blank popup pages? They're annoying as heck.