[SSG 520M] Issue with bootloader upgrade

Hi,

I try to upgrade the bootloader because of the message:

********Invalid DSA signature

********Bogus image - not authenticated

but when i finished to fill the different fields i optain this new messages:

Initiating hardware and waiting for link up ...
PHY read timeout on Port 0 (Ctrl=0x0000)
PHY read timeout on Port 0 (Ctrl=0x0000)
PHY read timeout on Port 0 (Ctrl=0x0000)
PHY read timeout on Port 0 (Ctrl=0x0000)
PHY read timeout on Port 0 (Ctrl=0x0000)
PHY read timeout on Port 1 (Ctrl=0x0000)
PHY read timeout on Port 1 (Ctrl=0x0000)
PHY read timeout on Port 1 (Ctrl=0x0000)
PHY read timeout on Port 1 (Ctrl=0x0000)
PHY read timeout on Port 1 (Ctrl=0x0000)
[Ethernet0/2 and Ethernet0/3]

and the link remain DOWN.

I plugged the ethernet cable on port 0/0 of the firewall. i tried with a cross cable and a straight cable.

I tried to force the ethernet port on my PC to 1000 full or 100 full and with auto-negociation but the interface remain down.

Has anyone ever encountered this problem?

Thanks you in advanced for youir help