D/c'ing at HT? Any possible solutions?

Quite frequently since the implementation of HackShield, I've been d/cing at HT quite often. I get two types of Errors:

1. My screen freezes, goes black, and d/c's with no error message what-so-ever.
2. My screen freezes, goes black, and gives me an error message of (-469696500) or something.

I've had a stroke of luck i guess this past Sunday at HT. I made it through 2 HT runs w/o d/cing. But today, I tried to HT and i d/c on prelim head with no error message. In addition, today while we were at prelim head near the end, everyone suddenly stops attacking on my screen. I'm the only one attacking for a good 10-15 secs. Then people suddenly starting to attack on my screen. My computer tried to catch up with the sound and animations. I was frozen for about 5 secs and my screen went black, causing me to d/c.

I'm using a Laptop with Windows XP: Media Center Edition.

I have 2 GB of RAM and Radeon ATI X1600 for my graphics card.

Is there any way of fixing my problem? Any comments would help.

In addition, today while we were at prelim head near the end, everyone suddenly stops attacking on my screen. I'm the only one attacking for a good 10-15 secs. Then people suddenly starting to attack on my screen. My computer tried to catch up with the sound and animations. I was frozen for about 5 secs and my screen went black, causing me to d/c.

Not entirely sure about the other 2 lags, but this one is internet connection related. Maybe some auto-updates, some internet leechers that download pron, etc..