Hacking Problem with EF3 + JLH: The Flash

[VVoltz]

Hi, I'm using a EZ3 for a month now, I've read everyting on their forum, and followed every instruction on how to set up this thing but:

I can't flash 'The Flash' game to the NAND section fo the cart, the percentage stops at 4% and some text appears on the bar and the rom is showed, but then when I unplug the cart, the ROM is no longer there!
Iv'e tried several relesases of this and no luck, anyone with a similar problem? or at reast some word of advice please?