When opening a .pro file in Eclipse Helios, a regular Eclipse text editor window is opened instead of the graphical .pro editor window which is shown in the integration documentation here:
http://doc.qt.nokia.com/qt-eclipse-1.6/images/profileeditor.png

This issue is visible under Windows 7 as well as Linux with Eclipse Helios and the Qt Eclipse integration 1.6.1.

According to a report on the Qt Developer Network ( http://developer.qt.nokia.com/forums/viewthread/601/ ), Eclipse Ganymede was the last version where this worked.