Are you sure you're doing it at the EXACT time? If it's a fat PS2 it may do that a lot 'cuz my fat took a lot longer to read it than the slim (IDK WHY).
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Consoles:
Original Xbox, 1.0 TSOP flashed w/ 500gb HDD
PS3, Rebug 4.82
Xbox 360, Halo edition Jasper RGH1.2