The problem is quite easy to explain, but I haven't found a solution yet.
The following are the hardware/ software I have.
In my home
PowerMac G5
OS X 10.4.10
Apple Remote Desktop 3.1
At Uni
Ibook G4
OS X 10.4.10
Apple Remote Desktop 3.1
Internet connection at home
Cable modem (NTL/Virgin)...
