Importing keymap does not clear unassigned keys

After exporting a keymap from Qt Creator it can be imported back for example after a reinstall.
What annoys me though is that Qt Creator won't clear keys that are not set in the keymap file. The import process simply leaves unassigned keys unchanged in the current configuration. So, if I import a keymap which has these shortcut assignments:
Editor-Redo | (empty) | (empty)
Project-Run | CTRL+R | (empty)
over a current configuration that has:
Editor-Redo | CTRL+R | CTRL+Shift+Z
kaboom: now I would end up having the same CTRL+R shortcut for two different actions:
Editor-Redo | CTRL+R | CTRL+Shift+Z
Project-Run | CTRL+R | (empty)
This issue might create a conflict in the assigned shortcuts. It affects all versions of Qt Creator, starting from 2.8.0 (the first that I know to do this) up to the most recent 3.2.0

And, most annoying thing: I have previously created a keymap with just the 10-15 shortcuts that I usually use. But because unassigned keys are not cleared, I have to spend 10 minutes scrolling down the 100+ keys in the list, clearing them, and just after I can import the keymap with my shortcuts.

So, to fix this bug you have 3 solutions:
best solution: Make sure unassigned keys in a keymap are cleared in Qt Creator's configuration as well
fast solution: Add a simple "Clear all" button that clears all shortcuts
other solution: When importing a keymap, simply replace your configuration file (wherever that file is, I could not find it anyway) with the new file. I'm not sure it's possible but might be a solution.