Dear All,

Thank you for your precious support. I would like to mention that Apple delivered a new firmware. After that I restored factory defaults and selected a specific and hidden option: g only mode. To do that you have to press option key (ALT) and click on the "Radio Mode" menu (in airport panel).

Also I selected WPA/WPA2 Personal (before was WPA2 only).

Now it looks working, so the incompatibility may reside in the mixed environment where the n and g saving power options can produce a buffer overflow.

Best Regards,
Mattia

References
http://www.macosxhints.com/article.p...80415163013760

P.S.
This is not the behavior that a serious router should have...