Steps to reproduce:

• have a Qt4 in PATH and start Qt Creator with clean settings (do no use Creator from a Qt package)
• go to Preferences -> Build & Run -> Qt Versions
• check that Creator has only detected the Qt4 version, and add a Qt5.2 version
• hit Apply and add a kit on the Kits page for the Qt5.2 version
• create a new Qt Quick UI (QtQuick 2.0)

Current result:

• Creator marks all Qml items unlined with a warning (M324 using Qt Quick 1) although the only applicable kit (Qt5.2) is selected for this project

Note: Restarting Qt Creator with the newly created settings and re-opening the last project/session makes these warnings disappear. Seems as if QmlParser uses only the Qt versions or Kits which are known at startup, but ignores currently added versions/kits.