spnar,
just like RC said, the two curves are not connected, also extend the stcok definition line,notice that when you try to clean and convert you get two dashed lines with a gap which may be indicative of something not connected and of course it dosn't clean and convert.
yes, you can use the tolerance setting, but I CHECK EACH START AND END POINT ( PROPERTIES IN ACAD) TO MAKE SURE THEY ARE CONNECTED that just eliminates a problem
comment: i havn't the foggiest idea what some other cad or paint programs may produce in terms of accuracy; ie we are dealing in 4 or 6 decimal places and some program may be in pixels....... or whatever
rich
on to A8