Simple? hang-ups with Corel Draw x5

I am trying to manipulate shapes with little success. Neither Cntrl nor Shift keeps the original shape, when trying to alter the shape using the shape tool and nodes.

Also, I'm trying to delete one segment of a polygon, but can't figure out how to do that. I'm sure the answers must be simple, but I can't get it to work.

Holding down the Ctrl key when moving an object constrains it with CorelDraw X5 for me.
To remove a node from a polygon, select it and go to the Arrange Menu>Convert To Curves.
Use the Select Tool (F10) to select a node, then press the Delete key.
Bob.

Thanks for the response. Cntrl and Shift work to constrain the object while re-sizing when it is just selected, normally. But I want to be able to re-size a pentagon--making the 'base' thinner and the 'top' wider. I selected it with the shape tool so that I could work on individual sections, but when I try to drag a node, the edges of the entire shape misform. I'm not sure how to re-shape a shape.

Oh, I found it. I had to convert the object to curves, then select the shape tool.

Thanks again!