Korg Poly800/EX800 Users

I dont know, but every time i send a sysex file with dumpster to my 
EX800, i dont think that it worked 100%. There are some patches that 
sound very strange, i think that dumpster sends the file too fast?
What do have to check, can someone give me a detailed description of 
how i get a sysex (the factory patches) into my EX800? I also tried 
the tape, but unfortunately my EX800 never says good at the end of 
the wav file? I did everything thats mentioned in the manual?
OK, maybe a hint?

Thanks!