Worker becomes disconnected when running in another window

[jheretic]

If the extension is open in one browser window and a second window is open, the extension will run correctly in the new window but only until the original window is closed. At that point, it seems as if the worker is freed, and attempting to run a test does not do anything. The console gives the following error:

console.error: mlab-browser-ext:
closing/deactivating: undefined
console.error: mlab-browser-ext:
starting test: NDT
console.error: mlab-browser-ext:
Message: TypeError: this.worker is null
Stack:
Mlab.prototype.startTest@resource://gre/modules/addons/XPIProvider.jsm -> jar:file:///home/n0n/.mozilla/firefox/9kk4rm8l.default/extensions/jid0-Bd5XamXyfqbUmirOfunzZx2ASYM@jetpack.xpi!/bootstrap.js -> resource://gre/modules/commonjs/toolkit/loader.js -> resource://jid1-btnb7inrquoaaq-at-jetpack/mlab-browser-ext/lib/mlab.js:203:3
emit@resource://gre/modules/commonjs/toolkit/loader.js -> resource://gre/modules/commonjs/sdk/event/core.js:96:9
portEmit@resource://gre/modules/addons/XPIProvider.jsm -> jar:file:///home/n0n/.mozilla/firefox/9kk4rm8l.default/extensions/jid0-Bd5XamXyfqbUmirOfunzZx2ASYM@jetpack.xpi!/bootstrap.js -> resource://gre/modules/commonjs/toolkit/loader.js -> resource://gre/modules/commonjs/sdk/content/sandbox.js:330:25
emit@resource://gre/modules/commonjs/toolkit/loader.js -> resource://gre/modules/commonjs/sdk/event/core.js:96:9
onContentEvent/<@resource://gre/modules/addons/XPIProvider.jsm -> jar:file:///home/n0n/.mozilla/firefox/9kk4rm8l.default/extensions/jid0-Bd5XamXyfqbUmirOfunzZx2ASYM@jetpack.xpi!/bootstrap.js -> resource://gre/modules/commonjs/toolkit/loader.js -> resource://gre/modules/commonjs/sdk/content/sandbox.js:371:23
delay/<@resource://gre/modules/commonjs/toolkit/loader.js -> resource://gre/modules/commonjs/sdk/lang/functional.js:208:20
notify@resource://gre/modules/commonjs/toolkit/loader.js -> resource://gre/modules/commonjs/sdk/timers.js:40:9