I just pushed a fix for bug 453256 to the comm-central repository.
What this fix does, is to take advantage of the fix for bug 143065, to make sure that the accesskeys that we use in the Display, Composition, Privacy, and Advanced prefpanes are now much more sane, than they used to.
Prior to this fix accesskeys were shared across all tabs, so that if Advanced/General used "A" for "Automatically..." then Advanced/Update couldn't use A as an accesskey. That resulted in a lot of inadequate accesskey choices.
So dear localizers: If you haven't already taken advantage of the fix for bug 143065, please do so now and improve your accesskey story in the Thunderbird preferences window.