On a feesh install mga4 b2 with new /home i do not have the problem.
But on the machine where i did a fresh install of the system, but reused /home, i have the weird problem that double clicking i.e a *.txt text file on the desktop, nothing happens except i get a icon in system tray that say kwrite is loading. It never do. Or in Dolphin if I i.e double-click .xsession-errors , dolphin hangs...
If i select to open with leafpad or gedit it works.
I can start kwrite from a terminal, but it takes much longer to start than gedit.
I can also start kate, but it takes a minute to launch...
I guess one configuration in KDE somewhere is not OK. Where...?
No panic, i have set the system to open text files using gedit, but it is not "the right way" to do it.