Using xulrunner, when I copy a link (type c, then the link number) and then switch to another app and
paste, I get the expected result. However, using 'firefox -app', I find the previous clipboard contents
being pasted; that is, no new data has been put onto the clipboard.

OS X, Conkeror head, FF up-to-date.

Nothing in my rc modifies copy/paste/kill/yank behavior.

Further data point: no new data has been put onto the internal clipboard/killring either.

Can't paste/yank data copied from other apps into Conkeror either.

This bug looks like it may be relevant:

https://bugzilla.mozilla.org/show_bug.cgi?id=541485

Starting up with '-safe-mode' next as suggested in above bug's comments does not even run conkeror, just
default Firefox in safe mode.

I'm not sure how to determine whether this is an upstream bug or not.