I have found there is a bug when using splines in AutoCAD 2012 LT and AutoCAD 2012. After creating a spline I am able to freely adjust the control vertices to create a contour. If I then edit the spline using SPLINEDIT and adjust the weight of a control point as required it causes problems with moving the edited control point. I have attached an image to show what happens after moving the control point a very small distance from its original location. I have tested this on my work computer running AutoCAD LT 2012 and at my AutoCAD course on the instructors computer running full version 2012.
SPLINEDIT > Edit vertices > adjust Weight > Next > adjust weight to 1.5 > eXit > eXit > eXit
I have then grabbed the grip for the control point and moved it to the location shown in the image. The original spline is shown as the dashed line and the red dot is the original control point location.
What I have found is there is a relationship between the adjusted weight and the distance the control point moves away from its position. The distance I am required to move the mouse is also scaled depending on how much I adjust the weight by.
The only way I have found to regain proper control of the point is to either undo, change the weight back 1.0 or to change the spline to "Show Fit Points". Doing any of these options removes the weight adjustment made.
Has anyone else experienced this bug or knows how to fix it?
I see the bug as well, the fix may be SP1, whenever that arrives.