well if you got a router it's much easier vs using a crossover cable.
but if your trying to transfer in game .ISO files and stuff of this sort i would recommend you use Quix with Avalaunch as those work pretty well together as far as loading a iso in quix and then transfering it to the xbox.
me personally i use XBMC (with MC360 skin. makes it look like the xbox360's interface) as a dashboard.
but as far as Craxtion it's been a while since it used it... but if it aint working i would try another dashboard on your xbox (like XBMC or UnleashX etc) and make sure the craxtion network settings are setup correctly etc with the username/password and port etc.
p.s. if your planning on transferring a decent ammount of stuff to and from the xbox i would strongly recommend getting a router (i recommend linksys) as that makes it soooo much easier and convenient... plus you can stream video files that are located on the pc end of things and watch them on the xbox through XBMC etc. u just gotta setup file shareing blah blah blah