test run stalls on Windows 7 in *test zzz receipt update*

[mykmelez]

On Windows 7, when running make test against Firefox release (23.0.1), the test run stalls in test zzz receipt update:

info: r2d2b2g: executing 'r2d2b2g/tests/test-main.test zzz receipt update'
…
info: r2d2b2g: Simulator.onMessage getIsRunning
info: r2d2b2g: Simulator.onMessage getDeviceConnected
info: r2d2b2g: Simulator.onMessage listApps
info: r2d2b2g: Simulator.sendListApps
info: r2d2b2g: Simulator.onMessage listTabs
…
info: r2d2b2g: [JavaScript Warning: "Unknown property 'box-sizing'.  Declaration dropped." {file: "resource://r2d2b2g-at-mozilla-dot-org/r2d2b2g/data/content/index.html" line: 0 column: 52 source: "padding:0;margin:0;border:0;display:block;box-sizing:content-box;-moz-box-sizing:content-box;-webkit-box-sizing:content-box;"}]

cc: @nickdesaulniers

[nickdesaulniers]

Does the order of the command line arguments affect the order the tests are run in? For example, test zzz was named so that it would be run absolutely last in the test suite. If it runs before receipt, it will break the receipt test. It's super brittle, but the best we could do before @bkase left.