QML signals example doesn't work under Linux

i'm using Qt 4.7.0.
trying to build'n'run qt/examples/declarative/cppextensions/referenceexamples/signal example, it builds ok, but the run output is:

QDeclarativeComponent: Component is not ready
An error occurred

debugging shows that it can't load example.qml from resources (":example.qml"). tried to use ":/example.qml", but useless.
removed ":", it worked ok.

maybe that's a resource system bug?