I just compiled and installed Vim, Vundle and [YouCompleteMe](https://github.com/Valloric/YouCompleteMe) plugin according to the introduction on Github.
But the YouCompleteMe plugin doesn't work well in my Vim. It can auto complete the variable's name but it doesn't auto complete the operation of STL objects (vector, map). It can't even auto complete the "this->" in a class. It always tells me "(^U^N^P) Pattern not found."
Have you guys seen this before? 
I use Ubuntu 12.04.
What should I do?