The Launchpad page seems more or less dead, so I'm cross-posting here (bug report: https://bugs.launchpad.net/dell-sputnik/+bug/1048816).
I am a Sputnik Beta participant; as such, I have the high-end XPS 13 along with the custom Dell Ubuntu image.
My hands are large enough that one or both of my palms hit the touchpad quite often while I'm typing. For this reason, along with the fact that I can't stand it anyway, I disabled tap-to-click via the Mouse and Touchpad settings program. I also enabled the "Disable touchpad while typing" option. However, the part of the touchpad that my palms normally make contact with (the left and right button zones at the bottom) don't seem to be affected by these settings. I can still tap-to-click on it. Indeed tapping (not depressing the clickpad) on either of the two mouse button zones results in a left click.
It's quite frustrating to be typing in one place and a brush with your palm results in the cursor moving. It happens constantly! Disabling tap-to-click should affect the entire touchpad.
EDIT: I'm very sorry, I didn't notice that someone already created a topic regarding this: http://en.community.dell.com/techcenter/os-applications/f/4613/t/19460455.aspx . If this bug affects you, make sure you indicate so at the bug report: https://bugs.launchpad.net/dell-sputnik/+bug/1048816 .
UPDATE: Fix has been released in the Sputnik PPA. You should be able to update and have this problem fixed.