Default [Q] can't use debug mode, after investigation: /sbin/adbd Segmentation Fault

Hello,
I have p760 with firmware V20F. Some time ago I have tried to install cyanogenmod but I failed with security error. After some work I have recovered to original android from LG. I have rooted it. Now I can't connect to pc in debug mode. I found out that problem is with /sbin/adbd which when I run with root privileges I receive:

[check_LGE_official: enable_root = 1
Segmentation fault

On notification area there is android icon for debug mode but it doesn't work.

How can I avoid this? does /sbin/adbd file can be replaced with another one?

Thank you in advance.
Grzegorz