I find it hard to connect with Emplode because my Empeg's IP address keeps changing. No big deal, I just check what it is each time & set the options accordingly.
You shouldn't need to set a specific IP address. If your computer and the empeg are on the same network, they'll get compatible IP addresses from the DHCP server and then the "network broadcast" option should work every time.
Of course, if you're not using a DHCP server, then both devices (your PC and the empeg) are probably setting somewhat random addresses each time they boot and you should set up fixed addressing for both devices.
In any case, it sounds like you're running into some kind of network communication issue. How much do you know about IP networking? Answer that so we can know what level of advice to give...