1) In VFP9, SP1 modify a report
2) Select Variables from the Report Menu
3) Click on a variable well down in the listbox (you must have at least a few variables defined)
4) In the Value to Store textbox (assuming you have a fair amount of text in it), left click on the right side of the box and drag to the left and purposely continue dragging past the left edge of the box into the listbox over the first variable in the listbox before lifting the mouse button.
5) Notice the variable selected becomes the first variable and the values in the controls change corresponding to the first variable.

It's a bug in VFP's form/control/mouse interaction. I believe it can be reproduced outside of the Report Builder by creating a similar form from scratch.

This behavior issue was unofficially reported; it can't hurt to report it again.

- Colin