Unique Networking Issue

My home network is setup as thus:

Cable modem->G-Router->:

1 Laptop running Vista Home Premium 64 bit connected wirelessly- in and out of sleep/shutdown
1 Desktop running XP Home connected wirelessly- always on
1 iMac Running OS X Leopard connected wirelessly- in and out of sleep/shutdown
1 Xbox 360 connected by ethernet- on and off periodically

The problem I'm having is that the iMac is sometimes unreasonably slow with Safari. The program loads fine, but pages, embedded videos, etc. take forever to load. I'm thinking this may just be because there are alot of machines on the same router.

I went to the router's control panel to make sure the systems were getting ip addresses correctly and I found out that the Mac seems to have two ip addresses or that there is someone stealing my wireless.

Any help would be appreciated.

Most wireless issues are to do with reception. Try raising the router above furniture level, swivel the computer and/or router antenna.

Move the computer nearer the router -- or against the wall nearest the router.

Relocate cordless phone base, video sender etc away from computer or router.

Try changing channels -- especially if you cann detect neighbouring wifi within 5 stops of your channel.

The utilities which came with your wireless adapter should include a scan facility which will show surrounding wireless points -- should show channel number of each.

Windows' own wireless networking controls may show channel depending on version.

You could also download NetStumber (freeware) which is more comprehensive.