Hello.
I'm trying to use Inkscape to make Entity-Relationship diagrams. I need create an Autorelationship-set, which is a relationship-set that connects twice, the same object.

How can I do that? I know that I can put two connectors with the same objects, but, always are displayed one over the other (which looks like only one connector).

Thanks.
Fernando.

Could you show us an example of what an entity-relationship diagram or autorelationship set, is supposed to look like?

Possibly you have snapping enabled, and the 2nd connector line is accidentally snapping to the 1st one. But that's a fairly big guess, since I have no idea what this diagram looks like.