I see this problem too. Occasionally parts of the web page becomes huge; I usually notice it here on launchpad.net (see screenshot). Before I saw this bug report I hadn't realized it's dual-head related.
I regularly switch between one screen configuration (14" widescreen laptop at 1280x800) and another (same plus an external 19" 1280x1024 LCD; combined to a 2560x1024 desktop) with xrandr (via the new Screen Resolution applet). The internal LCD is about 85 dpi, the external one about 75 dpi, and I've no idea what Firefox thinks the combined dpi is, but it is obviously wrong. Fonts look fine in single-head mode but huge in dual-head mode. The font size change doesn't take effect immediately after an xrandr invocation, but only when I reload the page in Firefox. ** Attachment added: "screenshot of Firefox rendering launchpad.net with huge fonts" http://launchpadlibrarian.net/14360096/firefox-fonts-suddenly-become-huge-in-the-middle-of-a-page.png -- Bizarre huge fonts in Firefox https://bugs.launchpad.net/bugs/224471 You received this bug notification because you are a member of Ubuntu Bugs, which is subscribed to Ubuntu. -- ubuntu-bugs mailing list ubuntu-bugs@lists.ubuntu.com https://lists.ubuntu.com/mailman/listinfo/ubuntu-bugs