network internet sharing

please help me i have windows vista beta 2 with two network cards,one is the internet and one is the network connected with a switch with other computerts.The problem si this one:i put the ip's the i shared the internet and the windows automaticli makes 2 network list one the internet one the network witch one has one of the network cards,and its works very fine,at one moment the 2 network cards apears in one network list after a minut or thwo it works fine with one network list but the other network list has no network card,after feo minutes the network is changin back,and the process repeats again and again.why???????????:) please help me,sorry for my enghlis i hope you understand what i sad:)

please help me i have windows vista beta 2 with two network cards,one is the internet and one is the network connected with a switch with other computerts.The problem si this one:i put the ip's the i shared the internet and the windows automaticli makes 2 network list one the internet one the network witch one has one of the network cards,and its works very fine,at one moment the 2 network cards apears in one network list after a minut or thwo it works fine with one network list but the other network list has no network card,after feo minutes the network is changin back,and the process repeats again and again.why???????????:) please help me,sorry for my enghlis i hope you understand what i sad:)