Couldn't login after activating it

I installed the plugin this morning, and it seemed to work. I logged out, logged in and this kind of errors appeared in the screeen:

Warning: call_user_func_array() [function.call-user-func-array]: First argument is expected to be a valid callback, ‘deprecatedSL::log_file’ was given in /home/nielbaul/public_html/wp-includes/plugin.php on line 406

Warning: Cannot modify header information – headers already sent by (output started at /home/nielbaul/public_html/wp-includes/plugin.php:406) in /home/nielbaul/public_html/wp-login.php on line 368

I couldn’t login again until I renamed this plugin’s folder.

Complete error messages at: http://pastebin.com/uXBu1SAc

http://ww.wp.xz.cn/extend/plugins/simple-feed-stats/