Confirmed in Firefox 7.0.1 here -- I'm the original reporter on Ubuntu bug 703191 (listed under "See Also"), and I have manually patched Cairo on my own system using Ingo Ruhnke's patch (attached to freedesktop.org bug 40456). This solves the problem system-wide EXCEPT in Firefox.
Confirmed in Firefox 7.0.1 here -- I'm the original reporter on Ubuntu bug 703191 (listed under "See Also"), and I have manually patched Cairo on my own system using Ingo Ruhnke's patch (attached to freedesktop.org bug 40456). This solves the problem system-wide EXCEPT in Firefox.