I can’t see the most recent email received. I switched over to the “new look” and I still can’t. If I hit reply, in new look, the most recent email in a thread will appear in the answer. “Expand all” does absolutely nothing, other than make the bar reading “10 previous emails in this thread” disappear. I’m not seeing anything in my settings that would seem to have anything to do with this.
I was having this issue yesterday. I tried most of the things you did and wound up having to forward the email I was trying to read to my Yahoo account, where it opened just fine.
It resolved itself after a couple of hours, though. Maybe just check back later?
Did you recently get updated to Firefox 8? I’m having this same problem. (I don’t think it’s anything to do with the new look, as you can switch back temporarily to the old look, and I have the same problem)
Speaking of Gmail’s new look–what do you think of it? I think it’s too spaced out. I can’t see as many emails per page as I used to be and I think it wastes space.
You can change the spacing between messages by going up to the little gear icon in the top right of the screen, and under where it says “Display Density,” choose “Compact”.
I don’t like the new look, either. I miss my customized colors, and I don’t like how the buttons have picture icons instead of text labels. What’s so wrong with reading, huh?
I had trouble when I “upgraded” to Firefox 8. Expand All did nothing, the message was simply invisible. If I tried to reply, I got a message saying “rich text editor couldn’t be opened”. Egad.
One suggestion was to re-open Firefox in safe mode, i.e. with all addons disabled. That would work for one message, then not so much.
Somehow I stumbled across another addin, that supposedly makes gmail work better with Firefox, and that appears to have solved the problem.