when i go to emplode it says the version of emplode is not compatible with the unit.

You might not need the serial upgrade cable just yet. I mean, you definitely need it eventually, but if you want to get things working fast without a trip to the store, you merely need to match your emplode version to your player version.

What version of the player software is on the unit, and what version of emplode did you install on the PC? (Find out by selecting ABOUT on the player and ABOUT in emplode.)

If the player is at version 2.0-something, and the emplode is at 1.0-something, then upgrade to the latest emplode (2.0 beta 13 at this writing, available from the links above). And if it's opposite, then dowgrade emplode to 1.03 (also available from the same place).

Remember to deinstall the existing emplode before installing another version.