okay after messing with flash0 I discovered A. It is surprisingly hard to brick your psp and B. The media player engine and files have changed. One file mcore.prx went from about 80kb to 7.4kb. msvideo_main_plugin went from about 370kb to 320kb but on later firmware mp4avc.prx (name probably completely wrong) exists and takes about 40kb. Replacing mcore did nothing, while replacing msvideo gave me an unresponsive xmb after selecting memory stick under video... I want to believe this is the file I need. Anyway, for now Im back on 5.0 M33-6 because it plays my anime. I must say hell cats recovery flasher is a useful tool and I must express my frustration as I do all my work with psp filer and my memory. Maybe when Im ungrounded from the pc I can figure this out... until then 5.0 M33-6 for the win