With Gecko styles aren't reliably cleared. Example
http://www.guardian.co.uk/commentisfree/2010/oct/30/google-polluting-internet
screws up paragraph spacing (too close together).
Seems to be fine with webkit.
The issue is that for some reason on first run not all stylesheets
are disabled in firefox. Subsequent runs are fine. Presumably it's a
bug in firefox; should report it to them.

When run as a bookmarklet in firefox, the first run it hasn't registered
simplyread() by the time it is called. Subsequent runs work fine. This
occurs whether simplyread is in a separate javascript: clause or not.