Similar issue can also be reproduced using the confirmation aspect of the ace:tabSet Proxy demo:

tabSet > Proxy, all browsers, Myfaces specific, v. 2.2.5 & 2.2.7
After entering input and selecting an option to either save or not save the input on the Confirmation tab, user is redirected to the previously viewed demo page.
This happens only once, in a cleared browser.
Steps:

• open showcase Overview page in any browser.
• navigate to ace:tabSet > Proxy demo.
• enter input text on Text Entry tab, and click on Confirmation tab -> Confirmation tab displayed.
• select any option to save or not save the input, click on Outcome tab -> redirection to showcase - Overview page.

Added f:ajax[execute=@this] facets for the yes/no buttons to avoid executing the navigation form.
Myfaces evaluates this binding in showcase.xhtml

            <f:viewParam name="exp" required="false"
                         value="#{navigationModel.componentExample}"/>

during post-back while Mojarra does not. This changes the selected demo after the first post-back to the default page (the component overview) since the parameter evaluates to null.

Verified ICEfaces 4 trunk r44152. Myfaces libs, Tomcat 7, IE 11, 10, 9, 8, FF 34, Chrome 40.

Re-opening to correct other showcase demos having similar problem:

1) dateTimeEntry > Indicator Text: user is redirected to previously viewed demo when submitting a new date.
To reproduce:

• open showcase built w/MyFaces in a cache-cleared browser.
• go to dateTimeEntry > Indicator Text.
• open the popup calendar, select a date and submit.
• open again the popup calendar, and submit a new date -> redirection to Desktop Showcase Overview page.

2) progressBar > Push: user is redirected to previously viewed demo when starting, then pausing the progressBar.
To reproduce:

• open showcase built w/MyFaces in a cache-cleared browser.
• go to progressBar > Push.
• start the progressBar, then click the "pause" button -> redirection to Desktop Showcase Overview page.

Seems like most of the demos that use a submit button are failing in the manner described above.
Other demos failing
dateTimeEntry > Overview, Popup, TimeEntry, Restrict Min/Max, Label Position, Required Styling.
submitMonitor > Overview
list > Selection, Reordering, Drag & Drop
sliderEntry > Submit.
dataTable >Selection
dataExporter > all demos
tableConfigPanel >all demos
tabSet >Server side
dialog >Overview
breadcrumbMenu > Overview
contextmenu >Per Component
menuBar > Dynamic
growlMessages > Overview

Often this server warning seen when encountering the issue:
Mar 04, 2015 2:42:02 PM org.apache.myfaces.shared.context.flash.FlashImpl _manag
eFlashMapTokens
WARNING: Identifier for execute FlashMap was lost on the postback, thus FlashSco
pe information is gone.

A more efficient solution for showcase may be to modify the NavigationController to not navigate away from the current demo if the navigation parameters are not defined.

Checked in fix for dateTimeEntry demos at r. 44171.

Checked in fix for progressBar > Push at r44172

Modified NavigationController so that navigation is avoided when the request is a post-back with no 'exp' parameter defined.

Verified ICEfaces 4 trunk r44181. Tomcat 7, FF 34, Chrome 40, IE 11.