You apparently created custom output presets for version 10. (10 and 11 have virtually the same output options.) And you can do it again if you'd like.
Click Share/Computer/Quicktime and, from the preset menu, select HD 1080i 29.97. Then click the Advanced button.
In the Advanced settings for video, set the Frame Rate to 30 or 60 and set Field Type to Progressive. When you click OK, you'll be prompted to name and save this setting as a permanent preset.
Could you recheck your question regarding AVCHD and QuickTime
a. I suspect that you really meant 1080p under Premiere Elements 11 Publish+Share/Computer/AVCHD versus Premiere Elements 10 Share/Computer/AVCHD. Is that the case,
b. You can always create a QuickTime 1080p under the Advanced Button of the preset, but that does not sound like what you are asking.
Do you have the latest version of QuickTime installed on each of the two computers?
I do not understand what you mean by 1080p Quicktime export options. If it is 1080p any format, you need to create this preset in PrE10 from one of the AVCHD export options as the base. Select a close-enough AVCHD export preset and then click on Advanced button. Here you can customize it to the setting you want and you should be good to go...
Looking forward to your follow up to help all help you with your question.
This is what I think that you are recalling incorrectly in going from Premiere Elements 10 to 11? I will supplement my previous post with this screenshot of the Premiere Elements 11
AVCHD (not QuickTIme)
that I think you seek. Does the following screenshot reflect what you are looking for?