If you haven't already grabbed the latest update for Snow Leopard, you may want to. Looks like it has some pretty important fixes:

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This update is recommended for all Macintosh computers running Mac OS X Snow Leopard 10.6.2 and includes fixes for the following:

• Inability to turn AirPort on or off in some cases after upgrading from Mac OS X Leopard
• An occasional loss of network connection when using Wake on Demand
• Inability to create a computer-to-computer network, or share the Internet connection on some MacBook, MacBook Pro, and Mac mini computers
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