Your IP Address is being used by another computer keeps coming up a lot, Is that someone hacking into my broadband would you say or is that something that comes up on the Mac and I just don't know about it?
shouldn't be getting this a lot, but it can be changed in your router settings
what happens is the router allocates an address for each of the devices on your network
for me I have
192.168.2.2
up to about
192.168.2.10
8 different devices, last digit just changes
I think as default, the computer gets to use this address for X amount of days, then it requests another from the router, sometimes if machines are off, then when it requests a new one, it can take an expired one from another machine (which can give the message you are seeing)
for me, I configuring my router to say that the lease time is forever, so they never expire, so once a machine gets its address, it keeps it
you can also turn off DHCP on your router, and manually configure devices
If thats makes any sense
it's all to do with how your router handles DHCP