I have the same problem. My mymsn.com homepage is now useless. Much of the personalized content has disappeared, and the content that remains is not functional. None of the links work. I cannot customize anymore or add content. My home page still works fine in IE8, and in FF3 on my laptop. I need to get rid of FF4 if this is not solved very soon. How do I return to FF3?

Also, I notice that the FF4 taskbar icon functions differently the FF3.x versions. I have an icon in the taskbar to launch FF. When I launch FF, I get a second icon on the taskbar. Previously, the launch icon would get a pale white box around it to indicate it was started and if I opened another FF window, a second box would appear around the launch icon. This is how the Microsoft application icons function. Please give this functionality back.

I see that the 4.0.1 update has fixed these issues. Thank you.

Okay let's get it together fire fox, this little embedded thing, now I yall can work things out so why all the stumbling around?....And it all seem to happens after or around midnite.....Peace

how do I get the 4.0.1?

It should come as an update. If not, go to the "Firefox" menu -> "Help" -> "About Firefox" There should be a button there to check for updates of, if it has already been downloaded, apply the update.