Wireless Router Problem

My Specs:

Linksys SRX 2000
Wireless-G Broardband Router

Model #: WRT54GX2
Serial #: KKJ00EA09216

I am having MAJOR problems with my internet. We have 4 other computers connected through wireless. We have had this router for about a year now and for the past few months the internet has been slowly going down, we would have to unplug the router and repower it back up. Now for the past 3 weeks now, it’s been going down so much nothing is working. I have shutdown the computer, checked for viruses and nothing is working.

I dont know if anyone else has these same problems or not? For my line of work I need to be on the internet a lot, and going down all of the time is not acceptable anymore.

Does anyone recommend a certain router?
There are also a lot of people in the neighborhood who use wireless, so if there is a certain router we can buy that will protect us from other users as well…please let me know asap.

** I am currently connected thru the main computer and not my laptop… I have my laptop next to me to see if it was problems with everyones computer being upstairs (main computer is downstairs)… and thats still not the problem… I still see the wireless icon connecting/disconnecting… but i’m still online on the main pc.

Just need to figure out what to do. Sorry to keep rambling. Any help would be GREATLY appreciated!

[edit] even the main computer is going down now too (but not as bad as the others)… but we have gone thru 3 other cable modems to see if that was the problem… and its not [/edit]