Can't use ImageRunner 2520 Scanner with MF Scan Utility error 255,0,0

Hello

I have trouble using the ImageRunner 2520 scanner with MF Scan utility on Windows 7.

The ImageRunner 2520 is connected through ethernet, and I can print with it on all my machines.

I have MF Scan Utility installed and ScanGear2 Tool installed too.

After I link the scanner with ScanGear2 Tool, I launch the MF Scan Utility but another printer is selected; MF620C which I no more have. Then after I try to scan with ScanGear on MF Scan Utility, it tell me error 255,0,0

Thank you for any help.