relation select in directional display endpoint and startpoint

Hi,

On a directional relation if source as multiple node type source, target can only have one specific node type,
If i use the relation select for this relation, the module show both source and target. If i set a relation, the endpoint is understanded as a startpoint, so if i save the node, it shows me this error:
The <em>xxx </em>relation type does not allow <em>nnn</em> entities as target..

I think this is a bug?