I see it was covered at https://discussions.apple.com/thread/3213463?start=0&tstart=0
Some seem to have found a way. But your machine, your risk.
Bob
Just upgraded to Lion the other day. I have my power options set to go to "display sleep" after 45 minutes and my screen saver set to "None."
Before upgrading I could wake my computer back up by jiggling the mouse. Now that doesn't work and I have to press a mouse button. A minor annoyance but wondering if there's a solution. My computer is an iMac, mid-2007, 2.4 GHz with 4 GB RAM.

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