The trackpad on my wife's 17" Macbook Pro seems to be failing. She'll be in the middle of working when suddenly it will stop responding to input. Both the tracking (i.e. mouse movement) and button clicking just stop responding. She usually has an external mouse plugged in, and this continues to work fine; just the trackpad dies.
She reports that it usually happens within a minute or two of beginning work. If she puts the machine to sleep and then wakes it, the trackpad will start working again for another couple of minutes.
Her machine is a 17" Macbook Pro from fall 2009. She's still running 10.5.8 on it. We'd consider upgrading to Snow Leopard if there's a good chance it'll help, but this really sounds like a hardware issue to me.
Is there anything we can try to fix this, or must it really be sent to Apple for repair? We do have AppleCare on it, but we're not too thrilled about having to be without the machine for weeks.