Tentative button not working

I am assuming that you're using Accudraw for this type of operation. THe pointer that is displayed would depend on which type of operation is currently being performed. If you have the Element Selection tool in operation it would display a circle with an arrow. If you're placing an element, like a line, it would display a white cross (+) and then a yellow cross (x) depending on your AccuSnap settings. The hand would display if you have selected the Pan tool in the view tools. If you press the right-mouse button this would reset to the previous selection.

Working with AccuDraw

I agree with what Andrew has mentioned. A hand usually indicates that you are in the Pan View mode. Just an FYI, if you want the cursor crosshairs to span the full view you can go in the User Preferences and select Input. There is an option to change the Pointer Size from regular to Full View.