[Brian]

Ah, dave - I just responded to your tweet, 'cause I saw that first. Thankfully, our forums support answers of more than 140 characters. :-)

It looks like automatic layout is turned on. (Maybe the template you started your document from did that for you?) If you open up the "Canvas" inspector, unchecking the "Automatic Layout" box in the "Diagram Layout" tab will stop that from happening.

The undo issue is something we plan to change in the upcoming 5.0.1 release. There's a beta build on our site, if you're not averse to running pre-release software.