The most common causes for a kernel upgrade failure are:

- Wrong kind of serial cable. Must be a null modem cable. Quick work around would be to use the sled instead of direct into the empeg, or vice-versa.

- Frayed serial cable. Common problem, happened to me. Buy a second cable.

- Problems with the serial port such as bad drivers, IRQ conflicts, using a crappy USB-to-serial converter. Try it on another computer.

- Using the wrong upgrade file. Try to flash version 2.0 final developer and see if that works. Don't use the alpha if you're having any kind of trouble at all.

- Corrupted upgrade file. Redownload using a download manager program.