I'm opening this thread because i think i have done everything is posted in the whole net to try to solve my problem, but at this moment i have been unable to.
Today i have recieved my brand new PSP-290, so i put it on my psp and tried to use with MapThis!. The homebrew detects it and says it's on, but all the signal bars are empty. This afternoon i walked all over my city to see if it was a problem of obstacles but didn't happen anything.
I have also repaired all my keys, exctracted the usb prx and replaced, decrypted and without decrypt... but still no work.