Nexus: The Jupiter Incident

Hi  

im not sure how many of you remember/played Nexus, but i recently felt like playing
it through again, so i reinstalled it. But im having some problems, that i suspect are down me using vista 64 (home premium).

basically if i try and host a LAN game, the game crashes to desktop with "nexus.dx9 has stopped working" - naturally windows cannot find solution  
The game does however run fine in single player, with the exception of one other problem; the pre-rendered cinematic videos' FPS suddenly hits a crawl about 30s or so in, which is not a MAJOR problem, but annoying never the less.

i have a feeling the mp issue might be to do with the direct play feature, as it has depreciated since XP, but im unsure.

any help would me much appreciated ^^

thx  

p.s. my bro has a very similar hardware setup to me (q6600, 4gb ddr3, 8800 ultra, vista 64 ultimate etc...) and he has the exact same problems, which leads me to believe that this is probably not the kind of problem that can be easily fixed