This is due to the SetUserPass() at http://bonsai.mozilla.org/cvsblame.cgi?file=/mozilla/xpinstall/src/nsXPITriggerInfo.cpp&rev=1.40&mark=142#132 used to generate the package list at http://bonsai.mozilla.org/cvsblame.cgi?file=/mozilla/xpinstall/src/nsXPInstallManager.cpp&rev=1.158&mark=278#271
DVeditz will you be able to fix this for b4?
The patch in bug 415034 fixes this
bug 415034 fixed on trunk
Fix checked into 1.8 branch
Verified in Mozilla/5.0 (Windows; U; Windows NT 5.1; en-US; rv:220.127.116.11) Gecko/2008031114 Firefox/18.104.22.168.