Hi. It's best to think (anti)clockwise with angles. Construct goes from right-facing at 0 degrees, clockwise as the angle increases.
The math is a bit of a pain when having to deal with the transition at 360/0, but Construct already has a condition for this in the System object, way at the bottom, under 'Values' - 'Angle is clockwise of...'
You can test for either clockwise or anticlockwise, but it's best to only test if you've determined that the angle has changed, because it tests true with no change.
I made a quick example here:
http://dl.dropbox.com/u/5868916/Angles.cap