I have a Linksys WRT54G wireless router.
A newer HP Pavilion laptop.

When connected wirelessly, the internet goes up and down about 3 times an hour.

This happens all times of day.
This happens on my wife's Mac laptop.

The router was replaced about 3 months ago because I assumed it was being caused by a faulty router.

I have cable internet and I live in a new housing development with, I assume, good connections to my house.

Now, for the odd thing. My in-laws have the same router. They live in rural Iowa. We went there for Thanksgiving and my wireless connected stayed up for the entire 3 days there (I know, 3 days with the inlaws!). This should rule out my laptop.

I have reset my settings twice on the router.

Could this be happening because of the fequency of the router, maybe its being disrupted by someone's cordless phone or something?

Any other suggestions?

Try keeping the MAC powered off and see if your laptop disconnects while the MAC is off.

If your laptop stays connected, you've found the culprit.

Its certainly possible, in a close-in housing development, that cordless phones and other wireless routers may interfere. You might try changing the channel (the 2.4Ghz channel) on your router.

Make sure the firmware on every component is up to date.

My wife is a teach and the MAC is only at home during the weekends.
Rules the evil mac out.
I called Linksys and they helped me upgrade to the latest firmware. I forgot to mention it.

I'll change the channel on the router this weekend.

Thanks!

Some wireless telephone systems interfere with wireless. Changing the channel is a good choice. There were nice programs for the MAC to evaluate wireless networks. They would give signal to noise ratios. This made selecting a channel a breeze. I'm not MAC now.

Some wireless telephone systems interfere with wireless. Changing the channel is a good choice. There were nice programs for the MAC to evaluate wireless networks. They would give signal to noise ratios. This made selecting a channel a breeze. I'm not MAC now.
There's a program called NetStumbler for the PC that will give you the signal strength and signal to noise ratio, too. It's pretty decent.

You might also try aligning the antenna on the router horizontally instead of vertically. If the antenna in the laptop is horizontal, it could help keep a better connection. (Weird, but it worked for me)

I had a client with the same problems he has wireless phones 2.4ghz. He got rid of them and everything worked, I found dlink to have less problems of this, this is in the same office and with one linksys and one dlink in the same spot, just my comment on what has happened with my client :)