Ok, so my screenshot didn't come through in the message. The message says "Printing Error: The Adobe Print Engine has failed to output your data due to an unknown problem."
This is the message that I'm not finding helpful. Help. Please.
Thanks for the screenshot tip. I was using a third party application (ScreenHunter) and although it showed up while I was typing the original post, it didn't come through once I'd posted it. But it's not necessary anyway, because it was just a window with the text detailed above.
I'll answer your last question first - why am I printing instead of exporting? A combination of force of habit and sheer ignorance. As it happens, I've just tried exporting it and it worked, so thanks very much.
This effectively renders your first question obsolete, but I'll answer it anyway. OS is Windows 7 and ID version is CS5.
If you want to track down the problem, try printing half of the document at a time, then break the ahlf that doesn't print in half, and so on until you isolate the page, then start removing objects until you find the one that ID doesn't like. That said, the recommended method is to export the PDF.