I and a friend got an issue that can be solve by switching the project in release mode if we are currently in debug. Rebuild don't fix it, that point is really curious.

In my case this error append when I decide to add a signal in a sub-class of QWebPage, to do this I also need to add Q_OBJECT macro. At this instant I got some vtable error but without any missing virtual method implementation. A complete rebuild don't works, but switching the current build mode works fine.

My friend don't remember the issue he got but he was also able to fix it in the same way.

Note my friend works under Ubuntu, and me under windows seven.