I too spent way to many hours trying to get multitouch to work on my 740. It is really annoying as the clickpad doesn't really allow both mouse buttons to be clicked at the same time for 3rd button mouse emulation. I have to use shift-insert instead for pasting between my browser and xterms.
The bug has been reported many times, I believe the problems are two fold.
1. There was never full support anyways, as you had to patch the kernel in order to get the elan touchpads to use the synaptics X driver.
2. The 740 along with some other newish samsungs have a newer hardware version (v.7?) of the touchpad, so the old patch does not work anymore. It is an odd beast anyways as the touch pad has 2 separate input devices, one like you would normally expect and another that only really outputs data during a multitouch scenario. I don't think the bug is considered high priority and it will really take an upstream fix to resolve this. :/https://bugs.launchpad.net/ubuntu/+sour ... ug/1166442