Im trying to downgrade my PSP 2000 to a OFW between 2.60 to 3.52 so I can upgrade to 5.00 M33-6 but I always run into an update problem. My PSP states

"The update cannot be started. The data is corrupted" when I try to install an update before 5.00 OFW. I was able to get on 5.00 OFW but thats as low as I can get on. I was able to go from 6.35 PRO-B3 down to 6.20 TN-D, and then to 5.00 but its not low enough to do any M33 CFWs.

Anyone know where I can find any working OFWs from 2.60 to 3.52?

The downgrade method I used was Davee's Downgrader to go from 6.35 to 6.20, and TN-D hen to spoof my firmwire to 2.60 so I can downgrade past 6.20.

All the OFW files I got off of this site.