The latest respond from IBM
IBM Update 2011-06-30 08:55
We understand your pain, but the old format is not going to be supported any more.
This is not a defect and the documentation for V8.5 is being updated as well as a Flash is being published to inform customer that the old Generic Index is no longer supported.
So, although we did not warn customers that this support was removed, we have not claimed it was supported in V7.1 or later either. We allowed customers to continue to use the old Generic Index file format in order to give them time to transition to the new format.
Even the question to the IBM OD collegues in Europe if they know a customer with the same problem have had no result until now.
So far, you are the only customer who has complained.