I recently downloaded Threads of Fate In order to convert it to eboot and play it on my PSP (note download was made with flashget) and the game has important bits of data missing once I open the file on the PSX2PSP program there is no save name, no game name, no save ID, I filled this and converted it to eboot and once I look it from my PSP the file is corrupted.
Most psx files floating around the internet(this site included) have minute errors though are playable with some emulators, are too corrupt for burning to disk or converting to eboot. Best option is to search for a better version or look for (redump) tagged version since those are the most accurate you can find.