[dpk]

I know this is an old post, but I searched around for other "UML Sequence" questions, finding none. Has anyone been able to figure out a way to create horizontal lines between UML Sequence boxes that does not require you to manually position the lines pixel by pixel?

I'd love to show you what I am talking about, but this forum makes it hard for people to post URLs. Search for "a quick introduction to uml sequence diagrams" and click on the tracemodeler.com link. I'm looking for that example diagram, without the blue trace line.

What I end up with instead can be found at 4yHA5.png on i.imgur.com. Two separate arrows, overlapping because of some automatic behavior.

I am using OmniGrafffle Pro 5.3.6, on OS X 10.7.