New CFW CEX Rebug 4.80.1 on PS3 superslim with 4.80 - gets error 8002F957

hi there

first post here...

well, i put my question on title, i do all the steps and check MD5, and get this error...

cex system with 4.80 OFW and try to install 4.80.1 downloaded from rebug site with md5 checked in a usb flash drive formatted to fat32 and put PS3UPDAT.pup files on PS3/UPDATE

error appear in 75%

thanks!!