That's terribly counterintuitive... please change it. I also would like to note that even for people who like the tooltips they don't work okay.
First of all, they always pop up under the mouse pointer, making it impossible to click on an item without moving the mouse away from the tooltip, possibly triggering a new tooltop (again under the mousepointer) when you accidentally move the mouse to the wrong item. This is the primary reason I've turned them off.
Secondly, if you actually want the information in the tooltip (most of the time it's useless) they don't stay visible long enough to be readable.
When you are dealing with rarely needed information that must be displayed for arbitary amounts of time, a dialog box is better suited than a tooltip.