I've updated the calibration UI so it should now work with AIMU, using the older (but proven) cal and sim3 utilities. The "Use DIMU" checkbox will select between the two versions. There is no reason to use QGC 1.3 any longer.
The updated software is included with the QGC 1.6 release, or can be downloaded separately from our site or FTP.
Cheers,
-Max