Yeah damned rt8192ce wifi driver is quite unstable now...
so I've added kernel module manually.
1. get the newer driver from Realtek site:
* rtl8192ce-va4 for Linux - ver.2.6.0006.0321.2011
2. unpack the tarball and make the kernel module (module was named r8192ce_pci.ko ).
3. copy this module into /lib/modules/2.6.39-3-generic-pae/updates/dkms/.
4. run depmod -a.
5. blacklisted both rtl8192ce and rtlwifi.
Then I could make X120e stable than before. :)
should I make dkms for it? :P