IDEA X - stepping over the line in debug mode is ofter very slow

Hi,
I have GWT project with Oracle DB.

When I invoke the code (after the web app started) even in Debug mode and don't stop it at any breakpoint, the code is invoked very fast, even lines which invokes methods operate on DB.
But when I make a breakpoint on such line and press F8 (step over) it takes around 30 second to step out of this line.

I have this problem even for code like (GWT client):
Button b  = new Button("asd");
b.setStyleName("qweq");

Stepping over these lines takes a few seconds.

Also I have to often wait around 10 seconds for IDEA to show me the values of variables while breakpoint.

Anyone have similar issue? What might be the problem?