There is no known hardcoded number for the model.db, but the EDU is hardcoded at 500 entries, have you checked the EDU?
Have you checked it with the model.db checker, mistakes are easy in this file?
Can you post a 'trace' log report?
Close, but it might be better asking the question here: http://www.twcenter.net/forums/forumdisplay.php?f=276