I recently haven't used my Mac Mini for about 5 days (however it was left on).

I seem to be able to connect and get great download / upload speeds through my PC, Xbox 360, iPhone and parents' laptop.

However, my Mac Mini is very slow.

OS X's Mail.app is downloading mail at 0.4kbps and then dropping to 0. Skype file transfers are doing the same. Browsing the net is a terrible experience. It is taking 30 seconds or more to download basic pages.

All of my devices connect wirelessly to a Netgear router / modem.

I have tried giving the Mac Mini a manual IP, and renew DHCP lease, as well as flush DNS in Terminal.

I have also rebooted the router / modem twice, and the Mac Mini twice.

Do you know what could be causing this? Thanks

Update

This is very weird. It is also very slow accessing localhost (setup through MAMP) and also slow to access the Netgear router config pages.