The dirty details are here:
The high level overview:
Some pages are failing to render (notably, msnbc.com) with the Fedora chromium builds. When those pages get processed by WebKit (in chromium), they were triggering a glibc double free error. This looks like a legitimate bug in chromium (or at least, in chromium's webkit copy), but tracking it down has not been easy. My Fedora chromium packages use system libs whenever possible (including making v8 into a standalone shared library), which involves a fair amount of patching and packaging voodoo. However, in the interest of trying to track down that bug and get it fixed, I've set that work aside and focused on reproducing the bug in a build from a completely "virgin" source tree checkout.
Unfortunately, when I do that, I hit another bug, preventing chromium from even building (I'm not entirely sure why I didn't hit this before in the packaged builds, except that v8 is built separately for me, so I may be sidestepping it entirely).
Evan Martin and Craig Schlenter on the Chromium team have been very patient and helpful in trying to debug this issue. Hopefully, we'll be able to get chromium building on Fedora again (specifically, I'm focusing on rawhide x86_64, although, all current versions of Fedora seem to suffer from this equally) and reproduce and then squash this pesky double-free bug.