To clarify what Tony said:

Unless you manually configure an IP address using emplode, the empeg tries to acquire an IP address with DHCP.

In version 1.03, if it fails, it doesn't assign an IP address, which is why you're getting "(none)" as your IP address.

Version 2.0b11 supports UPnP addressing. This means that if it can't get an IP address, it makes one up (beginning with 169.254). This is the same range of addresses as a Windows box will use when making up an address, so the two will generally be able to talk to each other. However, as you've noticed, the last two octets aren't stable.

The simple solution is to use emplode (while connected over USB or serial) to set an IP address. It's in File/Player Settings, IIRC.