Firefox 11 ignoring DPI setting in Windows 7!

Question

I loaded Firefox 11 on my new Windows 7 laptop. The display resolution on the laptop is 1900 x 1200 on a 15" display. So I changed the Windows 7 DPI to 120 dpi. Internet explorer 9 changes accordingly, but Firefox 11 does not.
I found online that I should change the layout.css.devPixelsPerPx property in about:config to 1.25. This works for the most part. But, for sites like Apple.com it completely messes up the navigation buttons on the top.
Why doesn't Firefox 11 work with DPI like Internet Explorer and Chrome do in Windows 7 and just adjust itself to work correctly with the different Windows 7 dpi settings? Anybody else have a better solution?

Answer 1

Several bugs have been filed over the years about following Windows DPI settings, and it's hard to tell which is the most relevant. You can register and "vote" for one or more of the bugs to be fixed, but there's no need to add a comment unless you can assist with a solution. (''Comments are emailed to several people, and "me too" or "still not fixed?" is called "bug spam."'')
[https://bugzilla.mozilla.org/show_bug.cgi?id=603880 603880 – Gecko doesn't apply system default scale on Windows]
[https://bugzilla.mozilla.org/show_bug.cgi?id=549919 549919 – firefox does not react properly on change of dpi scaling in windows]
[https://bugzilla.mozilla.org/show_bug.cgi?id=433664 433664 – font size does not increase with DPI setting]
[https://bugzilla.mozilla.org/show_bug.cgi?id=114270 114270 – Windows display resolution preference (DPI) is not reflected in UI for Mozilla's DPI preference (even though it's actually used instead)]