When you say crash, is it just the internet explorer window that freezes and you can still move the mouse and interact with other windows or is it a complete freeze?
Try a different video site to stream from. Also, make sure you have the latest Adobe Flash player and Java installed.
You can also try one stick of ram at a time (if 2 x 1Gb sticks). You would likely want to put XP SP3 on too as this contains some minor stability fixes for XP.