Is the Add-on Bar showing?

If so, try it with the Add-on Bar hidden.

Just the opposite. The Add-on bar was always off. When I turned it on I could scroll and copy again. I'd like to not have to leave the Add-on bar there, however. This must be a bug, should I file a bug report next?

I haven't had that problem myself, because I have the Add-on Bar open all the time. I recalledl seeing that issue being posted here by other users a few times. Guess I remembered that issue kinda bass-ackwards.

Sounds like it may be this Bug, which is related to a Full Screen or Maximized window.
https://bugzilla.mozilla.org/show_bug.cgi?id=644621
Was fixed, bur it was backed out for Firefox 8.0 and I can't figure out if it is supposed to be in Firefox 9.0 or not.
https://bugzilla.mozilla.org/show_bug.cgi?id=675865
Shows as "Assigned" and not "Resolved".

Thanks for rooting out the relevant bug report. Looks like the fix didn't get into v 9.0. What can I do to nudge them in the direction of fixing this? Will they read this thread?

The only "nudge" that will help is for someone to step up and fix the associated bugs. I doubt if the developers will see this forum thread.

It happens if there is no toolbar visible (opened) at the bottom of the Firefox window, so make sure that you either have the Add-ons bar or the Find bar visible.

Yeah, I will do that when I need to scroll-copy, but, that is a lame workaround til somebody gets what really needs to be fixed fixed!

I cannot italicize or bold here-this thing puts quotes around instead ?

That is OK. This forum uses multiple single quotes for bold and italic text (you can also use HTML tags) '''bold text''' and ''italic text''