Mark,

I run into this issue all the time, even this morning, a large part of my design was selected, I zoomed in on another part to check some details, some moments of inspiration later I detected an unused contour, deleted it, and then kept working. after half an hour I noticed the missing part, searched in my hidden objects, could not find it. Fortunately MoI has unlimited undo's, so I saved my work, it took me more than a minute to undo everything until the deleted work appeared again.

so yes, an option to deselect whatever is selected without holding the shift key would be nice.

wim