Thank you for your post.
There have been many changes since FileMaker Pro 5.5. I recommend downloading a trial version of FileMaker Pro 10 from our website (www.filemaker.com). When you launch your file with FileMaker Pro 10 trial, it will ask you to translate the file to FileMaker Pro 10 format. A new file is created as it reads information from your old file. In essence, your old file is not touched, so you can still use it in FileMaker Pro 5.5.
Then, with the new translated file, you should be able to scale your documents.