Display issues can sometimes be caused by registry settings changing. Take the following steps.
1. Close erwin Data Modeler.
2. Go to Start->Run, and type in REGEDIT, click OK.
3. BACK UP the registry first. Go to File->Export and save the current registry.
4. Then rename the folder from the following path
HKEY_CURRENT_USER\SOFTWARE\erwin\Data Modeler\9.96 so that becomes
HKEY_CURRENT_USER\Software\erwin\Data Modeler\9.96OLD
Then restart erwin DM