It's a bug, and a real pain.
If you really need to use Print booklet to output this job, there are two options: Make a new file and page by page copy/paste in place the content from the old to the new, which I know works, and palcing the pages from the current file into a new file, which I think works (but leaves you with having to make your edits in the original).
If you have Acrobat, you can do so from it.
As well, with Acrobat you can print booklet to its own print driver and have the second pdf should you need to reprint. No wasted paper using Acrobat if you review the resultant PDF either.