Think i found the problem.

When I open the recordset, i have to specify the type of locking it will use, i appended the following line to my code:

#DEFINE adLockBatchOptimistic 4

and then wrote again the opn statement:

adRecordset.OPEN("select * from schema.table order by field",;
adConnection,adOpenDynamic,adLockBatchOptimistic)

I changed some values, issued an UPDATEBATCH and everything worked just fine!

Anyway, thanks for taking your time to help me!