spurious "Incompatible Qt library" messages

A mixed C++/QML project which uses 'import QtMultimediaKit 1.1' and the 'Audio' element loads and runs ok on the simulator, but doesn't play any sound.

Among other things, this may be due to incompatible Qt libraries – here's the message log from Application Output window:

Starting C:\code\eg\dice-build-simulator\debug\dice.exe...
QMediaPluginLoader: Failed to load plugin: "C:/QtSDK/Simulator/Qt/mingw/plugins/mediaservice/qsimulatorengine.dll" "The plugin 'C:/QtSDK/Simulator/Qt/mingw/plugins/mediaservice/qsimulatorengine.dll' uses incompatible Qt library. Expected build key "Windows mingw debug full-config", got "Windows mingw release full-config""
QMediaPluginLoader: Failed to load plugin: "C:/QtSDK/Simulator/Qt/mingw/plugins/mediaservice/qtmedia_audioengine.dll" "The plugin 'C:/QtSDK/Simulator/Qt/mingw/plugins/mediaservice/qtmedia_audioengine.dll' uses incompatible Qt library. Expected build key "Windows mingw debug full-config", got "Windows mingw release full-config""
defaultServiceProvider::requestService(): no service found for - "com.nokia.qt.mediaplayer"

Part of the problem here is that the com.nokia.qt.mediaplayer isn't found – I've reported that separately, at http://bugreports.qt.nokia.com/browse/QTSIM-133.

The subject this report, is those crazy messages about the "incompatible Qt library". At best it's a distracting eyesore when you want to see a clean launch. At worst it's part of the reason why the audio functionality isn't loading.

There are six issues already containing the text "expected build key". One of these (http://bugreports.qt.nokia.com/browse/QTMOBILITY-405) claims that this problem can't be fixed. But there's no explanation of why.

Please either explain why this doesn't matter, or why it can't be fixed, or fix it so we get less noise while debugging.