Speakerphone automatically activated when ans. or calling on iPhone 4

Hello,

I have a problem with my iPhone 4.

It happened that the iPhone has been dropped. Visible damage were just a couple of spilled LCD crystal.

The front glass and LCD has been replaced, but now is another problem. When I want to call, immediately switch to the speaker, but I nothing hear and also do not hear me. (If I turn off speaker is the same)

The same thing happens if somebody calls me.

What is interesting is if I call from the SIP application, does everything right! :/