Powerdesigner joins in diagram

I have a lot of tables in my design and therefore many joins between them.

I try and ensure they don't cross each other too much (in fact I only have 3 lines crossing so far) so it easy to follow the links.

Unfortunately when adding an additional join/line PowerDesigner has a tendency to move all the lines connected to the object I'm connecting.

Is there someway to lock the lines in place so they stop getting moved around so badly.

Also PowerDesigner itself will sometimes put 2 90degree angles in a line - but I can't work out how to do it myself.

Is there a way I can create more circuitous lines rather than a direct line ?

Thanks