ahh the old 'brother changes the router config to confuse his brother' routine :P had you thought of that as a possibility?

I'm not even sure my brother knows what "router config" means...

also, reflashing 3.40 oe-a didn't work

I'm sorry to say this but it has to be the settings that you put into your PSP, i know you may deny it but if it was working on 3.03 (Official) and now it doesn't....

ok lets try and cut down some things.
are you using encryption? if so turn it off till you get this working.
are you hiding your ssid on the router/access point? if so unhide it again till you get it working.
does your router have mac address filtering and if so is it on? if it is turn it off for now.
now just make sure your in range of your wireless point and do a search for the network on your psp - it should see the ssid, there should be no encryption, and you will be able to get an ip address because your psp's mac addresses are not being filtered.
if it STILL doesn't work get something else wireless and connect it to your router/access point. if that works then your psp's wireless might be gone. if it doesn't work with another device then your router/access point is to blame.
see its all logical thinking. try this stuff out and then wee can take it from there.