> I think the problem may be, because we are using a PreparedStatment
> over and over with diferent parameters.

This should not change the picture.

> We have a great performance gain in this way.

Sure. That's exactly the reason they were invented long time ago :)

> You need code anyway?

Yes. I see the condition in getUpdateCount()

if (isResultSet || !hasMoreResults)
return -1;

and assignment hasMoreResults = false happens only in two places:
getUpdateCount() and hasMoreResults(). Both methods seems to be implemented
according to the specification.

Roman