Two other ideas.
(1) do you use an USB modem for your Internet connection ?
(2) you repeated spleep problems may be relating to overheating problem on your iMac. Is your G5 a rev.A.. i.e a machine bought before may 2005 ? Could you download this activity monitor (
http://www.gauchosoft.com/index.pl?t...source%20Graph)
and watch your CPU/HardDrive temp ?
Phil