Error with master page "insert current page number" when exporting book

Question

Using InDesign CS 5.5 for Windows
Recently upgraded from InDesign CS (the really old one from 2003). I did save a copy of all my old version files and kept the old ID installed just in case (after reading all the horror stories on here).
In my old version of ID, I created a book made up of about 70 documents. Some of these documents are one page, others have multiple pages. In the multiple page documents, I used the "insert ... current page number" character (or whatever the command was in the old version) on a master page, and formatted it to read, for example: Page 1 of 17, Page 2 of 17, Page 3 of 17, etc. When I exported my book to a pdf, it worked fine. (I do not want/have consecutive page numbers throughout the book, only in individual documents. By this I mean my entire book is about 280 pages, but not all of these 280 pages are numbered, just the groups of pages from these multi-page documents. It doesn't read page 1 through 280.)
Got my upgrade to 5.5 a few months ago, added some documents to the book, and (if i remember right) when I saved the book it asked to convert every old version document to the new version, which I said okay. When I exported the book to a pdf, some documents that are longer than 2 pages are now numbered wrong; the numbers are now going like this: Page 1 of 17, Page 2 of 17, Page 2 of 17 (supposed to be page 3), Page 2 of 17 (supposed to be page 4), etc. Every page but page 1 is now page 2 of whatever.
If I open the individual document and export it to pdf, the page numbers work fine. It's only when the document is exported with the book that the page numbers mess up. And it's not all the documents in my book; this error starts at a particular document and continues from that point throughout the rest of the book, affecting any document longer than 2 pages. Multi-page documents before this point in the book export with the correct page numbers.
I create new documents by doing a "save as" with a previously created document and cut and paste as needed, so I'm not having to reformat or set up page numbers on each new document. I don't use layers or styles (I'm sure there's a better way to do what I need, but I've only had time learn the basics, just enough to be functional.)
My attempts to fix this so far (using version 5.5), testing with the first document where the error appears: (1) I've removed the document from the book, deleted the insert current page number character, re-entered the insert current page number character, saved, exported the individual document to pdf and it worked fine. Put it back in the book, save, export, and it's wrong. (2) I took the document out of the book again, exported the document to .idml, saved as new .indd with new name, exported to pdf and it worked fine. Put it back in the book, save, export, and it's wrong. (3) I started up my old ID version, opened the old version of this document, exported to .inx, closed, opened .inx in ID 5.5, saved as new .indd with new name, exported to pdf and it worked fine. Put it back in the book, save, export, and it's wrong. (4) I moved the document up in the book order, putting it above a document that has correctly numbered pages, saved, exported to pdf, and this document was still wrong, but the one that has been numbered correctly all along is still correct. (5) I've compared settings for this document to others that number correctly and cannot find any difference.
It's like the page numbers get hung on "2" when I export the book, but only in the last two-thirds of the book. Sorry it's so lengthy, but I hope this description of my problem is understandable. Any advice, other than going back to my old version documents and starting over?
Thanks for your time and for all the awesome information this forum provides!
alice

Answer 1

Mr. Spier
Right after I posted my question, I saw a post from last year where somebody had similar problems. (I cringed because I spent almost 3 days researching this problem and never ran across that post; thanks for not scolding me for posting a semi re-run.) I decided to try one of the easier solutions: I opened the problem document from the book panel, went to the master page and deleted the text box containing the page number, copied the page number box from a document that worked correctly, and pasted it into the problem document. Saved that doc, closed, saved book, exported to pdf, and it worked!! The page number problem was fixed. I went back and did the same thing for the other problem documents and they all number correctly now. 
Probably not the best way, but for now this will fix it; I may have to do it again next time I add to the book. Although I didn't follow your instructions, I'll mark this as answered since it's working now. If it keeps giving me problems, I'll try the .inx export/new book route.
thanks for your time
alice