I can't use the 3d manipulator - whenever I attempt to drag the handles Blender simply repositions the 3D cursor.
In my experience (my laptop has this issue) it's a problem with OpenGL implementation affecting the selection. This causes dragging the manipulator to result in repositioning the 3D cursor instead of manipulating the object.
To resolve this you need to change the Selection option in the System tab of the User Preferences :
In my case, changing from 'Automatic' to 'OpenGL Select' resolves the issue.
I had the same issue on my laptop, and managed to fix the issue by turning off "Proportional Object Editing Mode" which looks like a little blue circle in the toolbar at the bottom of the page. (Shortcut O)
I discovered this because whenever I started a new 3D model with factory settings, the 3D manipulators would work perfectly fine, so I simply went through and copied all of the factory settings onto my project (I messed with a few things trying to fix another problem) and this was legit the last change I fixed and it was the only thing that made a difference for me.
EDIT: I know this post is old, but I thought I'd leave this here for anyone else experiencing the same issue.