I see that my trackpad (Acer Aspire notebook) is able to detect double touches with Synaptic drivers installed. Is it possible that to recognize multitouch gestures so I can remote control a Mac with OS X Lion?
The multi-touch on the newer Mac systems requires special hardware to detect the multi-touch events. The older MacBook Pro's will only detect two fingers down and are not considered Multi-touch.
Multi-touch capable laptops started with the MacBookPro 4,1 (the last MBP in the old body style)
If the Acer you are using does not contain the hardware to enable true multi-touch (sensing two fingers down is not considered true multi-touch) then it will not send those events through the NVC to the remote Mac.
Experience has played this out. When I VNC or otherwise remote into a Mac with my older Santa Rosa MacBook Pro I cannot use multi-touch on the remote system, even though the remote system is capable.
I would imagine the same is true for non-Apple systems.