Hi,
 
sometimes when drawing a rectangle with the rectangle comand or doing one with  a poliline, the vertices of the rectangle, if I apply a certain width, don¡t remain totally closed.  Sometimes the endings, due to the line's width, remain with a little failure. i.e. as the width is made since the axis of the line, as the endings of the rectangle meet, they don't fully close. Sometimes they do and sometimes they don't. Can anyone explain it to me ???
 
Thx a lot

It may depend on whether you draw the rectangle using the PLINE command as an open or closed polyline (finished by CLose). See the Properties of the selected entity - if it is closed or open.