You need to go back to the 5/27 Nightly build. There was a change in the code and broke Yahoo. Nightly builds can break anything at anytime. For anyone using the Nightly builds, this is common knowledge.

So the reason your nightly build works better than your Firefox build is probably b/c you have less stuff loaded in it.

Anyway, go back to the 5/27 nightly and stay there until this is fixed: http://ftp.mozilla.org/pub/mozilla.org/firefox/nightly/2014-05-27-03-02-02-mozilla-central/firefox-32.0a1.en-US.win32.installer.exe

You can watch this bug if you want: https://bugzilla.mozilla.org/show_bug.cgi?id=1017134

But if something breaks in nightly again, please don't be surprised. Just go back to the previous day's nightly. And this is coming from someone who's been using nightly builds for 10 years now. :)

The last few days of builds on Nightly development channel has had some issues with some since fixed and others still being worked on.

If you want to test the Nightly channel then hang out in Firefox Builds at mozillaZine.

• http://forums.mozillazine.org/viewtopic.php?f=23&t=2837021
• http://forums.mozillazine.org/viewtopic.php?f=23&t=2837315
• http://forums.mozillazine.org/viewtopic.php?f=23&t=2837591

This is the fun part of Testing the Nightly channel as there can be regressions and work in progress things going on at times.

Before the software update existed in the then early builds of Firefox 1.5, it was not uncommon for Nightly testers (like myself) to have at least a dozen separate previous builds installs. This was handy if some checkin(s) made the new build not useable in some way. Now days since most rely on the partial Nightly updates, one has to go download the previous build that worked or try to work with the current build as is.

Ok, this says it's a 32-bit build and installs in the x86 Programs folder. I want the 64-bit version.

Oh, and how do I know when the problem has been resolved?

You can follow the daily Nightly threads in http://forums.mozillazine.org/viewforum.php?f=23 to see comments on issues and when bugs are fixed and such.

The Win64 Nightly builds are not really supported like the Win32, Mac OSX 32/64 and Linux 32/64 builds are though as the Win64 Nightlies are more for to catch breakage/regressions. If a Win64 build or related server has problems it is not a priority to get fixed right away like say Win32 are. https://developer.mozilla.org/en-US/docs/Supported_build_configurations

If you really want to use Win64 instead then http://download.cdn.mozilla.net/pub/mozilla.org/firefox/nightly/latest-mozilla-central/

Well that sucks. 64-bit should be supported just as much, if not more than 32-bit versions. We're going to see the end of the 32-bit OS soon.