12.3,update to 4.10.1,network pb, reboot, freeze problems

opensuse 12.3 x86_64 , using networkmanager instead of ifup

i update the 12.3 x86_64 with kde 4.10.1
i reboot
firefox does not find the proxy. Firefox can connect to a web server with “direct internet”
yawp does not connect to weather server
skype does not connect to skype network
i reboot
all network pbs disappears
but fire fox does not find the proxy with “system proxy settings” and firefox finds the proxy using “manual proxy settings”
konqueror finds the proxy
i reboot
i can reach very rarely kdm even in recovery mode because of automatically reboot or freeze
when i can open a kde session during the opening system reboots or freezes even in recovery mode
one time i had a kernel panic, a software lock up

when i say “system reboots” it’s not a clean reboot but merely a brutal reboot. as if you press the pc reboot button

during previous days testing 12.3
i had only a minor reboot pb : almost each time when i boot, just before displaying kdm :
system freezes
system reboots

i suspect the nvidia driver

but at the second reboot no pb

is the “ondemand” power profile activated during boot ?
how to change it to “performance profile” ?