Thanks for your answer, walt.farrell. No matter how I set the tolerance (or if I don't set the tolerance) wherever I click or drag on the image, the whole picture (rectangle) gets selected. Sometimes the selection is spot on, but most of the time it isn't.
Is there a solution for the Flood Select problem where the tool selects the whole picture instead of for instance the sky...? There's a big contrast in brightness and yet Flood Select ( the magic wand) cannot find the borders..... I bought the program this afternoon, so maybe it's my lack of understanding things... Cheers, Willem.