JS error on Dashboard

Hi.

We've just upgraded to Foreman 1.6, and I'm getting JS errors in the
Dashboard page, so widgets are appearing stacked, rather than side-by-side,
and with no background. My colleague looking at the same server is seeing
things fine, though, so I was wondering if anyone had any ideas on tracking
the problem down.

It's Firefox 32.0.3 on CentOS 6.5 x86_64, with NoScript 2.6.9, but NS is
set to allow all scripts to run, and claims not to be blocking anything.
Even if I disable NoScript as a plugin, I get in the JS console:

Empty string passed to getElementById(). (26) application-a…:16

I'm taking that to indicate that the error is being generated 26 times in
loading the dashboard.

Apart from a warning about "Use of getPreventDefault() is deprecated",
other pages load fine.

Any help would be greatly appreciated.

Thanks,

Iain Hallam.