Hi,
The latest version (8.0.2082) for WISO Kaufmann supports the "DATEV-Steuerschlüssel" needed for transactions using "§3a/§13b Sstg.Leistg".
With this new version I am now able to export all the transactions from 2007 in DATEV format. The error messages that I reported at the start of this thread no longer appear.
Regards,
Andrew.