Double Lines When Creating Cad Detail from Section View

[j2narchitecture]

Hi.  Whenever I create a "cad detail from view" from a cross-section, I end up with double lines in the cad detail from view drawing.  When I go to erase a line in the drawing, there is another line underneath so I have to erase the same line twice to eliminate it.  Any suggestions as to why this is happening and how to correct it?  Any input is most appreciated.   I am using the current build of X9 and running it on my iMac.  Thank you kindly.