Extremely frustrating memory problem

Hello! I hate to ask for help in this way and believe me I've completely scoured the net for months on and off trying to find a solution to this myself before doing this but I'm at a loss. Most cases seem to be for After Effects and not premiere.

I use premiere pro 3 for editing and recently got a new computer. Its a dual core with 3 GB of RAM which i thought would be able to handle short projects in premiere but evidently not. I should say i use 2 third party effect packages, Boris FX and Sapphire and the memory does not handle this well, most of my projects cut out, give me memory warning messages etc so i have kept them really basic. I cant export any of them out to any format other than quicktime because it will fail and close down just rendering previews. I raised my virtual memory to 4600 but it doesnt help much. Im currently working on a project im really in to and it uses Boris's cartooner and composite effects, a few glows here and there from Sapphire and the thing is just dying. Its only about 3-4 mins long and i can barely open the project without premiere closing down, let alone finish it. The footage being used is just basic WMV and a few AVI files.

I have done a lot to attempt to remedy this, i run /nothing/ other than premiere and basic system processes. I changed my vista theme to classic and turned off sidebar, anything that drains memory. In premiere ive turned off audio wave form, thumbnails, set preview quality to draft and set the option for better memory performance in the preferences. Even with all this it seems Adobe simply cant handle the effects and I dont want to have to limit myself to using only the effects that Adobe likes. I'm not the most technically minded guy in the world, I get basic stuff but does anyone know if I can prevent this from happening? It doesnt have to be fast or fancy, i just want the damn thing to stop crashing on a project ive worked so hard on.