default gateway not available in windows 7

G'day,

While Windows 7 works and looks good, there is one major issue which threatens to derail the entire experience for me.

Several times a day, the default gateway becomes unavailable, which means that the PC running Windows 7 loses internet connectivity. At the same time, other PCs, running Vista, are continuing to work normally. This includes one PC with a WiFi connection and another which is normally wired.

The details of my network controllers (there are two) are as follows.

Description . . . . . . . . . . : NVIDIA nForce Networking Controller

   Manufacturer  . . . . . . . . . : NVIDIA

   Provider  . . . . . . . . . . . : Microsoft

   Version   . . . . . . . . . . . : 1.0.1.211

   Inf File Name . . . . . . . . . : C:\Windows\INF\netnvm32.inf

   Inf File Date . . . . . . . . . : Wednesday, April 22, 2009  12:47:44 AM

   Section Name  . . . . . . . . . : NVENET55.NDI

   Hardware ID . . . . . . . . . . : pci\ven_10de&dev_0373

   Instance Status Flags . . . . . : 0x180200a

   Device Manager Status Code  . . : 0

   IfType  . . . . . . . . . . . . : 6

   Physical Media Type . . . . . . : 14

The problem is solved by manually having to repair the problem when Windows 7 finds that the default gateway is not avaialble and resets network controller 2.

I have seen that this is not an isolated  with several reports on the net, some suggesting that a different driver might help, but which one? Any suggestions?