Internet Sharing Help

I've got an iMAC G5 and have set up Internet Sharing in the past that has worked with PC notebooks. I recently acquired an older G4 that has a D-Link WUA 1340 wireless USB adapter. This G4 worked fine using this wireless adapter from a PC connection.

I'm now attempting to share the connection on the G5 with the G4. The driver for the adapter finds the shared connection, and even says it's connected (signal strength between 70 and 80%), but I'm not getting ANY internet connection on this.

Please help! Appreciate it.

- DerbyDanX