Probably, disable model check function can solve it.
Step 1:
Click Start -> Run to launch the command line interface.
Step 2:
In the text box, input cmd.
Step 3:
In the command line interface, input telnet 192.168.1.1
for Windows Vista & 7, you have to go to “Control Panel – Program – Trun on/off Windows Feature”, Enable “Telnet Client” service.
Step 4:
Input your username and password: admin admin
Step 5:
Input the command sys modelcheck off.
Step 6:
Now go to the web page and upgrade the new firmware.
Step 7:
After upgrade/reboot, please go to “SysRestart” to restore factory default once, or the new firmware(function) won’t take affect !!

thanks that works.
but now another problem : i need annex-b for connection and not supported by new firmware.
any ideas?

Ok this worked, but now another problem: the new firmware is not support Annex B :(

any solution?