For the SVG graphic in the URL there are four horizontal bars to which a mask is applied. Parts of this masked area appear clipped. The size of the area appears to vary depending on the window size such that the larger the window, the less of the masked region that is visible. So far this has been reproduced on Windows 7 with Aurora both with and without Azure, and on Linux with Nightly. (Note that similar bugs: bug 779035, bug 797231, bug 779029 etc. all appear to be Windows-specific whereas this is cross-platform.) Appears to renders correctly in Firefox 16 but not 17.

Here is the file from the URL for posterity.

svg.display-lists.painting.enabled = false helps Regression window(m-c) Good: http://hg.mozilla.org/mozilla-central/rev/688734575830 Mozilla/5.0 (Windows NT 6.1; WOW64; rv:17.0) Gecko/17.0 Firefox/17.0 ID:20120802041638 Bad: http://hg.mozilla.org/mozilla-central/rev/074fb996dfd7 Mozilla/5.0 (Windows NT 6.1; WOW64; rv:17.0) Gecko/17.0 Firefox/17.0 ID:20120802062038 Pushlog http://hg.mozilla.org/mozilla-central/pushloghtml?fromchange=688734575830&tochange=074fb996dfd7 Regression window(m-c) Good: http://hg.mozilla.org/integration/mozilla-inbound/rev/a799b5bff84c Mozilla/5.0 (Windows NT 6.1; WOW64; rv:17.0) Gecko/17.0 Firefox/17.0 ID:20120801155239 Bad: http://hg.mozilla.org/integration/mozilla-inbound/rev/b077c43a4306 Mozilla/5.0 (Windows NT 6.1; WOW64; rv:17.0) Gecko/17.0 Firefox/17.0 ID:20120801163038 Pushlog http://hg.mozilla.org/integration/mozilla-inbound/pushloghtml?fromchange=a799b5bff84c&tochange=b077c43a4306 Suspected: Bug 776054

Thanks Alice for the regression tracking! Looks like this might be a dupe of bug 818841 (which may be partly a dupe of bug 797507).

Fixed by bug 806432.

Verified fixed FF 19b4 Win 7, Ubuntu 12.04 and Mac OS X 10.7.5

Verified fixed FF 20RC Win 7, Ubuntu 12.04 and Mac OS X 10.7.5