The website http://www.psp.docspages.com/ is selling software called PSP [Doctor} which they claim is a downgrader for Firmware 2.0, 2.5 & 2.6. Be aware that this is fake. There is NO downgrader for Firmware 2.01 and above (There is a legit one for 2.0 but this is not it).
Just a heads-up warning for anyone who comes across this and is not aware that there is no downgrader for the higher firmware. Thanks to PSP Hacks for the info.