I have been networking 2 systems for months now with no issues but suddenly it doesn't work. its a mac mini and a G4 500 tower networked over a d-link standard 4 port broadband router.

nothing is wrong with any of the cables or any of the hardware. file sharing is turned on with both systems. I can access the mini from the tower but not the other way around. this seems so odd and I can't figure out the issue. when I click on the network icon it does nothing. shows nothing at all.. not even itself.

I am a tech savvy guy yet I am totally stumped here. any ideas are welcome.

thanks in advance.
Mac mini C2D 1.83GHz - 2GB RAM - 200GB 7200rpm HD
Sawtooth w/G4 1GHz - 1GB RAM - SIIG SATA w/2x1TB HD
B&W w/G4 600MHz - 1GB RAM - 2x80GB HD
Sawtooth G4 400MHz - 512MB RAM - 40GB HD
Dell Ultrasharp 2007WFP 20" Widescreen LCD
2.94TB Total Storage