Xbuntu / AMD
Short description of error
When using the manipulator, if the scale-axis indicator you want to use is facing away from you then if you click it you'll start trackballing instead of scaling that axis.
Exact steps for others to reproduce the error
Turn on the manipulator (by clicking the transform tool)
Hover over the Y-axis scale indicator (the green one) and click it
...trackball is activated instead of the Y-axis scale...