This problem only existed in early versions of the InterBase ODBC driver The licenses that Easysoft supplied for these versions are case-sensitive and version-specific. You must ensure that you entered the license in the same case as the mail that you received with the license key. To check, examine this registry key:
HKEY_LOCAL_MACHINE\SOFTWARE\Easysoft\IB6
-Or-
HKEY_LOCAL_MACHINE\SOFTWARE\Easysoft\IB6U
If you find that the Serial Number was entered incorrectly, reinstall the software, entering the correct number when prompted. Alternatively, you can edit the Serial Number registry key value.