Sometimes a particular InDesign file may behave badly (if all your files are doing strange things, see Replace, or "trash" your InDesign preferences ). In such cases the first thing to try is export to .inx if you have CS, CS2 or CS3(InDesign Interchange format) by selecting File > Export… and choosing .inx from the file type dropdown, or if you have CS5 or later export to .idml. The resulting file should then be opened in ID and saved as a NEW .indd file.
Interchange format was set up to allow users to open files in a version of ID one release earlier (minus, of course, new features) than the one in which they were created. It reduces the file to the bare minimum of information needed to recreate the layout, and as a side effect it often strips out minor corruption that will cause strange behavior but is not bad enough to prevent the file from opening. Other things Interchange Format can help with are removal of stubborn unused swatches and references to missing plugins.
The .idml (InDesign Markup) format was introduced in CS4 and in that version you have your choice (.inx is listed as CS3 interchange) and is the replacement for .inx going forward. My non-scientific intuition says that .idml is slighlty less effective than .inx at solving problems, so I would opt for .inx in CS4 as my first choice, but I also would not dismiss .idml out of hand if I suspect document corruption.
moving pages in other documents: DIDN'T crash (therefore must be an issue with this particular document).
copying all pages across from the damaged document (dragging pages from the Pages panel) to a new document - same problem in new document.
deleted all the content from all the pages in the damaged document - DIDN'T crash (must be something in the content).
re-opened the damaged document and deleted one page at a time (followed by trying to add a page in the Pages panel to see if it crashed). Finally on deleting a particular page, InDesign stopped crashing.
re-opened the doc, deleted parts of that page (followed by trying to add a page in the Pages panel to see if it crashed) until it stopped crashing. Turned out it was a table that must have been damaged. I deleted that and now everything's working nicely!!! Huzzah