No graph or substitute table is shown on stats page in IE7

[claycompton]

In IE7, neither the graph for client usage or downloads per month, nor an accessible table showing the same information, is shown on the root stats page.

I’d expect tables like those that are shown in IE8, but it looks like capability detection is failing on this browser in some profound ways.

When this happens, the following client JavaScript error is reported by the browser:

Line: 386
Char: 9
Error: 'displayGraphs' is undefined
Code: 0
URL: http://qa.nugettest.org/stats