Attempting to get Lightscreen Portable to capture anything

Downloaded .5
Installed on both thumb drive and on hard drive as a standalone app
Using Windows XP Home edition version 5.1
When I double tap "LightscrenPortable.exe", I get the Lightscreen splash screen and a "Lightscreen" window containing a "Screenshot", "Options", "Hide" and "Quit",
Using the dropdown menu on the "Screenshot", I select "Area". Instructions state to drag a rectangle to select an area... I do that with a left click on the mouse and an area is highlighted. As soon as I let go, the area disappears and nothing happens... I can find no captured image. (I also tried the "Screen" and "Window" option and got same result, which is nothing.)
Please tell me what I'm doing wrong... I'm feeling really stupid right now, especially given all the rave reviews for this product over the last 7 months.

Thanks...Tom