I'm having the "waiting for retry" problem, too. I'm using:
Win2000 domain with Win2000 DHCP server, server machine ip 192.168.16.2 (it's also the gateway to the net).
WinXP for music server (DHCP assigned IP 192.168.16.17)
Java SDK 1.4.1_01. (has anyone gotten this to work with this version of Java?)
Original RIO server software.
RIO and Music server box both plugged in to Netgear 8 port switch (not a hub, a switch).
New server software installed at "c:\program files\trio-0.1.1"
Tweaked trio.xml to replace "f:\code" with "C:\program files"
Changed server ip in trio.xml to 192.168.16.17, didn't change the ports.
Changed broadcast-address to 192.168.16.255
multicast address still 230.0.0.1
replace receiver.arf.

Rio boots with the new .arf, it displays a trio splash screen.

TRIO server starts with the following output
Start of TRioServer
Start of ClockApp thread
Loading TRioPlayerLayout: scrolling
player app - Starting TRioUnit App thread
ImageTranslation: byte-binary
Creating sockets
creating udp socket. local port: 19680, timeout: 15000


ipconfig on the music server shows:
Ethernet adapter Local Area Connection:

Connection-specific DNS Suffix . :
IP Address. . . . . . . . . . . . : 192.168.16.17
Subnet Mask . . . . . . . . . . . : 255.255.255.0
Default Gateway . . . . . . . . . : 192.168.16.2

finally, netstat -r on the music server shows:
Route Table
===========================================================================
Interface List
0x1 ........................... MS TCP Loopback interface
0x2 ...00 08 a1 12 c0 50 ...... CNet PRO200WL PCI Fast Ethernet Adapter - Packet Scheduler Miniport
===========================================================================
===========================================================================
Active Routes:
Network Destination Netmask Gateway Interface Metric
0.0.0.0 0.0.0.0 192.168.16.2 192.168.16.17 20
127.0.0.0 255.0.0.0 127.0.0.1 127.0.0.1 1
192.168.16.0 255.255.255.0 192.168.16.17 192.168.16.17 20
192.168.16.17 255.255.255.255 127.0.0.1 127.0.0.1 20
192.168.16.255 255.255.255.255 192.168.16.17 192.168.16.17 20
224.0.0.0 240.0.0.0 192.168.16.17 192.168.16.17 20
255.255.255.255 255.255.255.255 192.168.16.17 192.168.16.17 1
Default Gateway: 192.168.16.2
===========================================================================
Persistent Routes:
None

Any suggestions?