Are you connected to the player properly? For example, when you start Jemplode, does it show you the empeg, and you select it, and it correctly downloads the player's database and shows it on the screen? This step is important, if it doesn't work, nothing else will work.

Also: Jemplode uses Hijack's FTP features to send the animation file to the player. Do you have Hijack installed? What version? Have you perhaps disabled or password-protected the Hijack web or FTP features?

Are you using some kind of a firewall product to protect your computer from network hacks? Such a product might get in the way of FTP transfers in some cases.