First, see
this thread
Next, you didn't provide many details about your problem. What software are you running? Player software version as well as emplode...
You might want to launch emplode FIRST with serial. Then make sure the player config is set to use DHCP for ethernet.
When you launch emplode, you will be able to change the way it searches for your player. In 2.0betas the button is labled OPTIONS. Press that and turn off all options except Network Broadcast (ethernet). Now wait a little while for it to search.
What port speed is your computer set to? As a test, if it is at 100Mbit/s, try changing the NIC properties to force it to 10Mbit/s. Now try emplode again.
Check the ABOUT menu on the empeg for your ethernet address - just to make sure it has had one assigned. (You can also connect up through a terminal (like hyperterminal) to watch the serial port as you power the empeg on. This will show you what's going on during IP assignment, etc.
You can also try changing your player to a FIXED IP address.
Also, when you said you had a HUB connected with cable modem, did you in fact mean a standard hub or do you have one of those linksys (or similar) routers? If you're using something other than a regular hub or switch, then you can probably manage the specific port on that device through a web browser (read you instruction manual). You might have to set the port up to map an IP to the empeg, or allow DHCP, etc..
The bottom line is... If you want more specific help, you should probably supply more specific information on your current setup.
You might also want to use the SEARCH feature of the BBS - there's a lot of archived information here that might be useful to you.
Bruno