Try changing your UMD ISO mode, press select to open up the VSH menu the change i from UMD to M33 driver.
First, is your PSP hacked? second of all, if it is, go to recovery menu (shutdown PSP and start up but hold R button) then enable vsh menu. (configuration - enable vsh menu) after, exit and go to XMB. press select a menu should appear. Change USB device to UMD Disc (make sure u have your UMD that you want to copy inside the system. then go to USB connection. open up your PSP's folder and you will find your game which u can copy (it should be named UMD 9660 but it don't matter. Make sure you COPY NOT CUT!
Completely shut down your PSP as in hold the power button up until the screen goes black. Then hold R shoulder button then turn your psp on. KEEP holding the R button and it should go into the scary black Recovery menu. Then choose what you want to do. If you have the option of turning on the vsh then do so, to make life easier when you want to quickly change a setting. Also check out psp wiki: http://alek.dark-alex.org/pspwiki/index.php/Recovery_Menu all your problems solved :)
One is made of paper And the other is a DVD/VSH
They are based out of Malvern, PA. Check out: www.wikinvest.com/stock/Vishay_Intertechnology_(VSH) for more info.
press select after you turn on the psp then ull see M33 VSH MENu go to UMD ISO MODE then change it by pressing left and right button make it Sony NP9660 then press exit.,.that's it u don't need to download anything in the internet.,hopefully that helps..
There are hundreds community-made bosses across the VSH servers, but the most commonly found characters are : Saxton Hale, Headless Horseless Horsemann Junior (Horse-MANN is the correct spelling), Vagineer, and Chistian Brutal Sniper.