I have often battled with the same problem -- one solution is to download and install the free trial version of PageMaker 7, open the old file there and save it as a new clean PM7 document.
That might have a better chance of not crashing InDesign.
Some crashes are caused by linked files not being found, so if you can unlink those (or all) while in PageMaker, that might also help ...
Great idea, finally got hold of a trial copy of PM7, opened and saved the files in .pmd format - and Indesign crashed as soon as I tried to open them. Back to square 1 unless I can at least get a .pdf maker to convert .pmd files to .pdf
Thanks for the reply.
It's been a while since I used it, but it seems to me one can create PDF directly from PageMaker 7, either in the Print dialog or Export... or Save As...
Thanks, the Export from Pagemaker 7 would not work as it needs acrobat distiller but I have managed to create a .pdf from the print option and then caombined various parts into a single .pdf using Acrobat 9 pro. A long work around but great result. Thanks.