Using a software screenshot in a paper When writing a paper which, as an aside, talks about the design of a user interface on a particular piece of software, can one insert a (correctly labeled and referenced) screenshot of the software to help readers understand - or does that cause copyright issues? 

For example, I wouldn't use a photo unless I held the copyright, or a diagram - but I'm unsure of the legal position of a screenshot...
If you're displaying the screenshot as part of a paper on user interface, the use of the screenshot will almost certainly fall under "fair use."  Make sure you cite the software properly, and you should be all set.