changing the scale tools mode to object, as pixal suggests, will stop this warning message.
So what does the warning mean?
This has happened to me in the past and I was curious to I did some fiddling and here is what I found. First we need to understand there are OBJECTS and COMPONENTS. If you move. rotate, or scale an object - like a cube - it's translation, rotation and scale values will be altered. But if you move the components of the cube - like the verts - it's translation, rotation, and scale values are not changed.
To see this create a cube and grab some vertices and move them around and look in the channel box and you will see the translation, rotation, and scale numbers do not change.
Now, with the scale tool in object mode (the default), scale the object in all three axis (drag the middle yellow box of the manipulator) and you see the x, y, and z scale values all change.
Next, just scale the cube in one axis by lets say pulling on the red x-axis handle you see the scale x value change.
Up to this point everything should be intuitive.
But now lets change the scale tool mode to world.
First scale in all axis again and note the the x,y,z scale values change. Okay that is no change from when it was in object mode.
Finally, scale along the x-axis and take note that the scale x value does not change in the channel box and you get the warning message that the scale has been baked into the components!
So when scaling along an axis in world mode it's like you grabbed all the vert (components) of the cube and scaled them this changes the position of the components (the verts) but not the scale values of the object.
So that is what is happening, although I am still not clear on why you get this behavior only when scaling along a single axis though.
The gotcha in all this is if you scale along an axis while NOT in object mode it has no effect on the scale so if you started with all the scale values at 1,1,1 and you scaled to 2,2,2 and then scaled (while not in world mode) 1 unit say along the x-axis then even though the object scale is now really 3,2,2 it will still say 2,2,2 and so if you set the x,y,z scale all to 1 instead of a perfect (1 1 1) cube you will have a (2 1 1) box!
"If I have seen further it is by standing on the shoulders of giants." Sir Isaac Newton, 1675
Last edited by ctbram; 16-07-2012 at 08:36 AM.