There seems to be a bug with the Polygon Lasso tool.
I am utilizing Photoshop on my MacBook Pro (new as of two years ago) with a Wacom tablet. I can use all the tools in Photoshop, even the Lasso tool, with the Wacom tablet. But when I use the Polygon Lasso tool I cannot make any points or lines. I have use my laptop's trackpad to successfully use the tool, or I have to reboot the whole computer so that I can use the tool with my Wacom tablet.