Intermittent internet connection problems

Hello,

I've been having a problem with my internet connection going down for a second or a few seconds at a time throughout the day. It happnes a lot in the morning. But it happens in the afternoon too. I know it goes down because my Winamp will start to say 'Buffering' or it will just stop, my MSN Messenger will get signed out, and I can't pull up a web page. Sometimes it is very brief though and my Winamp will just start playing again automatically after a second of being down and my Messenger will never get signed out.

Here is some more information:

We have DSL through SBC/ATT. We have other computers that are configured the same way and connected to the same switch that this is not happening too. It is only mine. I've ran Spybot Search & Destroy, Lavasoft's Ad-Aware (both numerous times and cleaned what they have found) and HJT. As far as HiJack This, I didn't see anything obvious that would be knocking my connection down. I thought I might have spyware that is just overloading my NIC. Oh, and when my internet goes down for these short seconds or several seconds, I still have access to our network - I can browse our network drives just fine. I have Windows XP Pro with SP2. I have ran Windows Update and have all the latest critical updates. I am still looking to find updated drivers for my built-in NIC (I have an ASUS Pundit R350 PC, and according to my Device Manager, I have a 3Com 3C920B-EMB-WNM Integrated Fast Ethernet Controller. We are running Symantec Antivirus 9.0. We have a Netopia Model 3346N DSL Ethernet Switch for our Router/DSL Modem.

Anyone have any ideas? This is driving me nuts.

Thanks.