This issue has been reported many times and with all the SCN-solutions/tips and OSS notes available, the problem still persists in our BW system.
We recently went from BW 7.3 SP7 to SP12, after which this problem started to show up. It's the exact problem as mentioned in note 1897899:
This note however, has been applied in SP11 and the coding is already present in our system.
Has anyone experienced the same, or should I create a support message with SAP?