Macbook(maybe Safari specifically) causes router/modem to fail... HELP

I have a Macbook 2.4Ghz. I have a Linksys router at home which works just fine. Here at work we have a 2wire router provided by AT&T. It was woring fine for a while, but recently the internet starting acting up here at work. I figured the wireless cutting out on the Macbook was due to that. But, I noticed that since the problem was fixed, I still get cut off. I have noticed that the internet on the work PC seems to work just fine... UNTIL I turn my Mac on. Once I start using the wireless that's when both my Mac and the PC start losing connectivity. The lights on the router start blinking red then go back to green. If I turn off the Airport on my Mac, the internet seems to run just fine on the PC.

Also, I tried out my friend's HP Pavilion and his wireless doesn't affect the router at all. I think there may be a chance it's Safari, because I tried Firefox and it didn't do it. I had Firefox on in the background and trie using Safari and it worked fine. I'll have to use Safari without Firefox loaded at all and see what that does. So I think it's pretty safe to assume that it's Safari or the at the very least the Mac that's doing this. But why?

Thanks in advance for any and all help.

P.S.
OK. So I logged out of Firefox completely(even right clicked on the icon on the dock and hit "quit"). And I used Safari again and it took about 2 minutes to give me the problem again. I'm back on Firefox now and no problems.

Also I forgot to add this pic(http://img145.imageshack.us/my.php?image=picture2bc9.png). This is one of the pages I get when the problem occurs.

Thanks again.