I've run into a major problem with simple line drawing that I do not see a solution to.

I have polar at 90 degrees, 
ESnap is set to ONLY "end point".
Commands are set to override Esnaps.

Draw a horizontal line.  Now I want to draw a line over that line, but much shorter.  I begin the new line at one end, drag my cursor along the original line, and enter a length command.  As I type the length, the endpoint that I started the line at is highlighted, and when i press "enter" a zero length line or point is drawn at the end point.

For instance, draw a 10 inch line.  Attempt to draw a 1 inch line on top of the 10 inch from one end.

If I drag my cursor much farther down the direction and enter the length, it works fine.  If I enable "nearest" in esnaps and it shows the icon under my cursor, it works fine.

The same behavior happens when I enable ONLY "midpoint" in esnaps, and draw a line from the midpoint.

Am I going crazy?  Please tell me the stupid mistake I am making.  I cannot use this software with this issue.