ash wrote:can this check be done when the user hits apply or atleas when he tries to enable the effects checkbox ? the way its now blocks access to other places in the desktop settings (like screen saver)

Cannot be done as an OpenGL call is made to see if the panel should list OpenGL mode and effects or hide them. As Mesa is supposed to fallback to software rendering mode if it's not supported by the system it is perfectly fine to make this call. I.e. this is not a KDE crash.

ash wrote:to zarin - in the safe mode which i want all effects are disabled and this check is not done either. the user can enable effects and click apply but nothing happens until he makes logout and login to standard mode

The "safe mode" you describe can be achieved by using a stripped down xorg.conf with all compositing, GLX, DRI and Render modules disabled. KDE is designed to neatly fallback if they are disabled (Unlike the problem you are getting at the moment which is where they are enabled and should be usable but are not).

you cannot expect the prefect condition you talk about on all computers. xorg can be screwed up cause of some update etc. and then comes the user who wants to use the computer NOW and not when his distro fixes his xorg in the next update / untill the friend who is a linux boy comes back from the year trip

a safe mode would solve the immediate problem for this user - well effects are disabled and oxygen theme does not look perfect without transparency etc but the computer works and thats what is important. and does not crash when the user tries to get to the screensaver settings

i'd make kde start into safe mode if the user holds down shift or F5 etc in the first few seconds of the kde splash screen

now about opengl - this can be done when the user hits apply. there are 2 options in the dropdown - opengl and xrender. so in the common case he'll get error message that opengl does not work and the computer falls to xrender. at most the user will get the crash but thats when he actually tried to enable effects