Inconsistent internet connection

Hi,
I posted a few weeks ago asking about a sudden inconsistent wireless connection. I tried a bunch of things to no avail, but now I've tried connecting my computer directly via ethernet and I still have occasional issues with my internet. Previously, I was using a wireless setup and the connection would drop every so often, so I tried changing the router, changing the channel, resetting everything, but nothing helped, and this problem was consistent on multiple computers. So I finally moved my router 3ft from my computer and still had connection issues, so I connected my computer directly to my WRT54g router which made things slightly better, but I would still get an occasional dropped signal or slow connection, and the yellow exclamation would come up. Now I'm connected to the modem directly, and its better, but I still get an occasional slow down or disconnect. What do you guys suggest? As I've simplified the system, the performance has gotten better, but not 100% from what it used to be. Are there things that I can check/do on my computer that may help? Everything (router, modem) seems to be working fine, the lights blink like they always have, until the connection drops of course, but could there still be an internal issue with the router or modem? Thanks.

The computer in question; is it a desktop or laptop? If a laptop, what type of or wireless connection is it using...ie G or N?

The WRT54G is still a pretty good router but is limited to G wirless speeds (54mbps) and LAN speeds at 10/100 mbps. A new router wouldn't hurt. A wireless N model that has up to 300 mbps with 10/100/1000 mbps LAN ports.

It's a desktop, but I'm not as concerned about the wireless anymore since a direct ethernet connection to either the router or modem is causing issues as well.

Check what version of the WRT54G router your using and see if there is a firmware update that can be applied.

Linksys - WRT54G Support

I updated the firmware to the latest version. I called my service provider and they checked some stuff out and they think there is something wrong with the modem or connection to it, so they're going to come out and check it out soon. Hopefully that will resolve my issues. Thanks!