final stumbling block on downgrade

Sorry to know doubt ask something thats been asked a million times before (done a search and couldn't find anything) but...

After following all of the instructions and finally getting to the part where i can finally download v1.5 my PSP just says "The system software on your PSP system is v2. There is no need to update."

Have i missed something that disables this?

Thank you

mph downgrader

Ive got that.

Got all the right files saved in the right folders and do the bit in the camera section, then when i go to the game directory and select v1.50 it just says what ive written above.