Check the bookmarked links, are they correct or old/corrupted?

Will the same links open in Internet Explorer?

I had to wait for it to screw up again, because it's not every time, every day. Okay, today same thing with Firefox...I couldn't open GMAIL or three other sites. I tried IE and the same thing. However, things returned to normal after I rebooted my computer, so do I need to do this every time Firefox is unresponsive? I might add, for what it's worth, I'm running Windows XP and connect as a guest on my router. The Internet comes into the house on a phone wire, to the ISP's little black box, then my Netgear router. ALl of this is on the other side of the house, and I get the Internet as a guest, wirelessly. My signal strength has always been excellent. Maybe my connection needs to be "refreshed" at times??

Mozilla says you replied but I cannot see your response. They seem too, to be so eager to have be say the problem is resolved when it isn't.

Note besides following this from emails you can also watch on the forum

• use https://support.mozilla.org/en-US/questions/970393

When you say

I tried IE and the same thing. However, things returned to normal after I rebooted my computer,

Do you mean IE is also becoming unresponsive. If so that may be an indication that whatever the fault is it is not Firefox itself.

You also said

I had to wait for it to screw up again, because it's not every time, every day. 

If it is an intermittent problem that comes and goes it could be a problem with your internet connection or for instance a WiFi problem; if that is how the computer connects.