If you in HANA have two users with same username but in different casing (we have asked SAP Support and they claim that this is a feature and not an bug (Please vote for this if you also disagree with SAP Support: https://ideas.sap.com/D38598))
This issue have been fixed in B1UP 2016.11 HF1 (http://www.boyum-it.com/sbo)