I'm using Adobe Acrobat 5.0 on Windows XP and am trying to delete pages in a PDF, but I'm receiving this error: "One or more pages are in use and could not be deleted." I'm not able to delete the pages. This happens with some pages but not all.

Specifically, I select Delete Pages from the Document menu, enter the page number (for example, From: 1 To: 2 of 9), then click Yes at the prompt, and then receive the error.

I've used Acrobat for several years and have never before encountered this error. The pages can be deleted from the PDFs when I use an Acrobat install on another PC. I've tried uninstalling and reinstalling, but the error persists.