Okay its pretty simple. I have a Linksys WRT54G router. Usually there's no problem but recently, its always been disconnected from the ISP.

If i use a direct connection from modem > pc/laptop everything's fine, but when i try modem > router > pc/laptop then its often disconnected, and even when i do get a connection its only for a minute or two.

I upgraded the firmware to the latest version and now im having a different situation. The router still disconnects frequently, but it quickly reconnects, using a brand new IP address.

This is fine for surfing but my instant messengers or downloads get cut off every minute.

My router's never done this before. I dont understand why this is happening now.

Any help will be greatly appreciated.