Left click clicks when cursor is moved

I am using a DELL XT2 with Ubuntu 12.04 Unity Desktop. As far as XT2's touch screen is concerned I always had problems, like random cursor movements, but turning touch screen off by magick-rotation always helped the problem. But this time turning off touch screen by magick-rotation does not help.

The problem is: when I move the cursor from one point to another, after one second it clicks (left click) itself without my control. I didn't see anything like this in any forum.

I need urgent help, it is really very hard to use the computer with this problem.