I happen to have dev-python/PyQt4 installed, but specifically installed app-portage/etc-proposals with USE="-qt4", and expected it should use the GTK interface by default... But the qt4 interface pops up instead. The reason is that /etc/etc-proposals.conf has this line as default, regardless of USE flag settings: PreferedFrontends=qt4,gtk2,shell It would be nice if the qt4 part was filtered out with USE="-qt4" (and the gtk2 part filtered out if USE="-gtk" too)
Fixed in app-portage/etc-proposals-1.4.3-r2