Thanks for your reply.
I have attached some error logs, i can`t understand where is the problem.
I have found this in syslog:

Jan 29 10:30:33 raspberrypi ntpd[1943]: ntpd exiting on signal 15

I am newbie on raspberry pi, but i have 2 SD cards with Raspbian. I have one microSD Sandisk with 8GB memory (with adapter). And one SDcard with 16GB class 10 from Serioux. I am not sure if I am doing something wrong but, with the microSD i didn`t have any problems yet, all works good. The SD card i...

I have the same problem, just bought a new Kingston SD card 16GB class 10 made in Taiwan.
Working with an microSD card with adapter but not with Kingston. I think i will return to the store to change it.
If anybody have an ideea I will try it..