Select tool acting weirdly!

[sl60]

My Magic Wand select tool was acting normally and then suddenly it stopped selecting (none of the settings have changed as far as I can tell). I selected part of an area with the rectangle select and that worked properly, but when I tried to select the rest the Magic Wand did nothing (it's set to "add to selection")--no selection. Then I tried it on a different area that has various parts seen through tree branches hat I need to select and it selected the entire area in a rectangle (as if it were the rectangle select). Any idea what's going on? Obviously there must be some kind of wrong setting but I can't find it.

Thanks in advance!