What happened is I set a region for in/out, then wanted to click in the time line to move some clips and Vegas reset my region because of my mouse clicks. It's very sensitive to the slightest drag of the mouse.
so is there a way to either turn off this dragging to make a region selection, so I just use I and O to do it, or can I lock the region so it doesn't change or move until I unlock it, maybe a right-click command?
Hit the "R" key to turn the selection into an affixed region. You'll see a pair of green markers, identifying the I/O points of the region. If you ripple, they'll stay with the ripple, depending on the ripple mode you use. If you want to erase/delete the markers, right click the green marker and choose "Delete."
Does that work for you?
You can also press the [<--Backspace] key on your keyboard to get back the last several timeline selections. So when you move your mouse, just hit backspace to get your selection back. But Spot's idea of adding a "real" region with the R key is probably best if you are dragging other clips into the region.