logout automaticly

[Jonathan]

I am using Ubuntu12.10.Every time I login and click to open a software that is used to connect the Internet,the Ubuntu logout automaticly.
And this time it shows a black screen which shows words as follows:
*checking battery state 。。。
*starting CUPS printing spooler/server
*stopping system V runlevel compatibility
*starting
*starting
*stopping
*stopping cold plug devices
*stopping log initial device creation
*starting save udev log and update rules
*stopping save udev log and update rules$ post_type