I'm a technical writer and Word is my only tool available for publishing documents. Most of the documents I publish are anywhere between 10-150 pages, and they are all created in Word and published in PDF format (converting with Acrobat).
It is rare to convert a document to PDF that doesn't contain any formatting errors that weren't there prior to conversion. More specifically, these things occur when converting to PDF:
-Page breaks are inserted after some Figure cross-references
-Heading styles change completely
-Some black text becomes blue
-Images are pushed on to the next page, even if it fit well in the Word doc
Considering that I do not have access to Framemaker or anything comparable, is there ANY way to prevent these changes when converting from Word to PDF? It's especially aggravating in longer documents, because I have to re-format them several times before most (but almost never all) of the issues are resolved.
What version of Word are you using? If you're running Word 2010 have you tried setting the Adobe PDF printer as the default and then setting "Use printer metrics to lay out document" under Options > Advanced > Layout options dialog in Word?
It is likely related to a common property of word processor as Lori has mentioned. Most word processors reflow the document depending on the printer. When you print to the Adobe PDF printer or use PDF Maker, the document will reflow to best match the printer, unless that Adobe PDF printer was selected in the print menu while you were editing. The printer metrics option is available in WORD to try to avoid this issue, but I am not sure how well it works. I have had similar problems with forms and such that folks prepared in word and could not print correctly to my paper printer because of the same issue. Changing the printer and going through the document to check the layout is the most reliable way to deal with the issue and it appears it is working for you.
You could try LibreOffice or OpenOffice for free equivalents. I would just suggest you might change your default printer to the Adobe PDF printer and then when you want to print to something else, change the printer then or create a PDF and print from the PDF.