Can you preserve ellipses from Illustrator when opening in Isodraw?

At work we have two seats of Isodraw (we are newbies) and we also have CS4 and currently there are three illustrators so one of us uses CS4 to create our art in then save down to Illustrator 8 and then we open in Isodraw and apply the callouts. The files then are saved as cgm's to use in Arbortext. The problem is when we open the files from illustrator in isodraw all of the ellipses are converted into beziers. Is there a setting to keep the ellipses? Thanks