Topic: BBT requires valid APPID and APPVER
I could not get Gnucash to work with aqbanking ofx until I set the APPID and APPVER in the user settings to QWIN and 1700. The values entered needed to be valid, i.e. using APPID=QWIN and APPVER=1800 would fail.
reference:
http://ofxblog.wordpress.com/ofx-appids/