Im having the same problem
1. Mac OS X. Vers 10.3.2,
2. OS X firewall (adjusted it to allow limewire: no success)
3. ram? Size: 256 MB
Type: DDR SDRAM
Speed: PC2700U-25330
(i think thsi is right)
4. HDD space available,
5. Connection type: Its through a compan called keycom at my university halls of residence. Its cable i think(ethernet)
Built-in Ethernet:

Interface: en0
Type: Ethernet
IP Address: 82.110.67.59
Subnet Mask: 255.255.255.0
Broadcast Address: 82.110.67.255
Router Address: 82.110.67.2
DNS Servers: 212.9.98.20, 212.9.96.21
Domain: as25178.net
Ethernet Address: 00:0a:95:de:94:a8

6. Modem & router brand name & model numbers:

Firmware Version: APPLE VERSION 2.6.1
Driver: InternalUSBModem.kext (v2.6.1)
Modem: Dash2 (V.92) Euro 1.0F
Country: B4 (United Kingdom)
Interface Type: USB


7. Where are you trying to connect from (home, school, work, etc.)?
Uni halls of residence: my room.