TYPO3 Core

Changing user account start-up module preferences creates JS error, breaking clickmenu for pagetree & filelist

user tools->user settings->startup-> "Start up in the following module" is set to "page module" the clickmenus for pagetree and filelist fail to pop

--repeatedly demonstrated with two discreet admin user accounts
first one is set as default.. (=clickmenu works)
the second set to startup in the page module (=js error)

using "reset to default settings" button rectifies

observed on one new install of 4.2.0 - no extra extensions
in Firefox 2x and ie 6x

firebug reports the following:
top.loadTopMenu is not a function
callURL("table=pages&uid=2&listFr=0&enDisItems=&backPath=|06498ca5b4&addParams=&bank=0")clickmenu.js (line 74)
show("pages", "2", "0", "", "|06498ca5b4", "&bank=0")clickmenu.js (line 47)
showClickmenu("pages", "2", "0", "", "|06498ca5b4", "&bank=0")clickmenu.js (line 218)
onclick(click clientX=0, clientY=0)alt_db_navframe.p... (line 1)
[Break on this error] top.loadTopMenu(this.clickURL + '?' + params);
(issue imported from #M8303)