APC and codeigniter -- benchmark::mark() undefined.

[eluser]mlakhara[/eluser]
Hello,
I recently installed APC on my xampp server on win7 and everything is running fine except the
fact that my codeigniter appplication is not starting and giving me this error.

Code:

Fatal error: Call to undefined method CI_Benchmark::mark() in C:\xampp\htdocs\cosys\cosys_initial\trunk\system\core\CodeIgniter.php on line 116

I googled to find something around this topic.
I saw this
http://stackoverflow.com/questions/27404...odeigniter
and tried to remedy my issue by using absolute path for system_path variable in index.php but it didn't work.
Please help me out.

/*********EDIT*******/
After commenting the line 116 I am still getting this error when there is any call to a CI class's method..