Disable portfolio creation when combining documents

I usually combine multiple files into a single PDF for posting on my parish website. The bulletins come in 3 or more files. Front cover, back cover, inside contents and maybe a bulletin insert.

I used to save the files to the desktop, highlight them and click combine.  That gave me a single PDF that I could post. Now I get a portfolio containing 3 or more documents. I am now forced to convert the documents individually to PDFs and them manually combine them into a single PDF.

How do I tell acrobat XI that I want all files combined into a single PDF and not a portfolio? I checked the preferences section and found nothing.  Do I need to upgrade or downgrade to get back to creating a single PDF?