My PSP reads [Model: 02g]
PRO Recovery Menu
Configuration
Hide MAC address (default this is Enabled)
You can guess what it does if you Disable it though
You can Enable it again after you set everything up
PRO Recovery Menu
Advanced
Use mac.txt in /seplugins
Never used that myself but I presume you can set your own mac address, best google how to set that up/use it, that option is Disabled though by default