Oh, and the server, two desktops, and Xbox can obtain/renew addresses fine.

Hi Touche112,

your described problem seems to be solved very easily. The different devices do not get an IP address through to an option in the switch webinterface. This feature is called Fast Link or Portfast.  

Fast Link — When selected, enables Fast Link mode for the port. If Fast Link mode is enabled for a port,  the Port State is automatically placed in the Forwarding state when the port link is up. Fast Link mode optimizes the time it takes for the STP protocol to converge. STP convergence can take 30-60 seconds in large network

So in webinteface enable option "Switch --> Spanning Tree -->  STP Port Setting --> Fastlink" for the relative port where the device is connected to or on CLI (Command Line Interface) 

console#configuration

console(config)# interface ethernet g1  | g1 for the port 1

console(config-if)# spanning-tree portfast

You can find more information to spanning tree in the manual
http://support.euro.dell.com/support/edocs/network/54xx/en/UG/PDF/en_ug.pdf (Page 304 - 311) 

Regards,

Rodger

I don't have an option in the GUI or CLI for STP Port Settings, or Portfast.  The manual you linked is for a 5424, I have a 5224.  :(