I might have known. As soon as the review below was uploaded I went back to the test project and, yes, Scribus started to freeze on me. The project contains 6 pages, 17 images, 6 linked text boxes, several discrete text boxes, file size 96KB (excluding linked image files). The same action seems to kill the program every time - switching on the "text flows around frame" button on the latest image. I've tried a lot of tricks, even rebooted. This is not a particularly large project so this has me concerned for future commercial uses of the application. (I eventually got over this impasse but it still worries me everytime I select the text flow option.)
What is interesting is the effect that a potential bug has on the user. If I had paid $1000 for this software I would be hopping up and down and cussing the company that sold me a "bag of snakes". As it is, I am still frustrated but also tell myself "but you paid nothing for this software".