VS Designer keeps resetting my properties

Question

It's really annoying, I have made a control which displays two boxes, which has two orienations - vertical or horizontal - which you can change by changing a property on the control in designer - which works fine. it compiles and runs fine and as I want However, then when you come back to the code, it has changed the orientation back to what it is by default. Unforuntalely the orientation changes the size of the control also, so it ends up completely wrecked I cannot think why it might be doing this. Anyone met it?