I saw an interesting issue today with a General Line Label. Here's how it looked in the source drawing. A user imported a general line label style and added the label to an existing AutoCAD object in the new drawing. The problem was that the arrowheads were pointing in the wrong direction. It looked similar to this label.
I compared the style settings between the source and destination drawing. Everything matched exactly. The only difference between the original label and the new label is that the original label was on a polyline and the new label was on a line that had an elevation of 500 for one endpoint and an elevation of 0 for the other endpoint. Once I set one endpoint elevation to match the other endpoint (both at elevation 0), the label then looked exactly as it was designed to look.
Lesson of the day #1: Sometimes polylines are a better choice than a line for labeling.
Lesson of the day #2: OSNAPZ to the Rescue.