plasma doesn't start automatically since 4.1.71

[Nick Shaforostoff]

I updated kde from 4.1.69 to 4.1.71 from opensuse repositories (11.0)
and plasma stopped loading automatically (just blank white or black
screen),
so i have to alt+f2, enter 'konsole' then enter 'plasma'

the problem stayed after i updated to 4.1.72.

I tried removing .kde4 but this didn't help. and btw, nepomuk + strigi
are still annoyingly ran by default. very very bad for a solid state
drive.

How can I debug the problem? (is there any logs?)

i use upstream branding (not opensuse).