Netbeans auto-suggestions doesn't work

[criminal]

I'm working on C++ project on Netbeans IDE 6.5. I have a std::string variable; when I place a dot next to this variable no auto-suggestion pop-up appears to help me with the list of functions I can use. Even after I press Ctrl+space it says "No suggestions". Any clue?

[criminal]

I just noticed that in some other file in the same project, auto-suggestions appear for a string variable. The file where it doesn't work is a .cpp file and is a php-extensions code.