>although my laptop would pick up an IP from the main machine using ICS.
Are you sure of that. If the IP starts with 169 then it most likely is not. See http://duxcw.com/faq/network/autoip.htm.
>I've connected the machines (from machine to machine via the cross over)and use the straight cables when goin through the hub
Until the problem is fixed, the hardware should not be changed. I would suggest that if the crossover cable is custom made that there is a higher probability that it is not as reliable as a stock straight-thru cable. If the straight-thru cables are also custom made, it does not make a difference which configuration you use except the crossover has the advantage of fewer things in the equation and the hub has the advantage of the LEDs for troubleshooting.
I have seen problems mixing some 10 MHz NICs with some 100 MHz NICs.
I lot of times uninstalling and reinstalling everything network fixes problems. Other times that is not sufficient and the TCP stack has to be reworked (http://duxcw.com/faq/network/winsock.htm). Larry