I was copying a large file from Microsoft Windows to Pages so I could work in a decent platform and everything was hunky dorey until I started the editing part. Neither the Bold nor the Italic buttons would work, but Underline would. I quickly learned that continuing to push them was not going to change things.
I closed and reopened Pages. Nope. I restarted my Mac. Nope.
I called the Apple Help Desk for help. The problem was the font that the Word document was using. It was plan old reliable Ariel, but nevertheless, the problem was there. As soon as I changed the Pages document to Helvetica the problem went away.
I could have chosen other fonts, but I think this is primarily a Word problem. The really sad thing is the person who sent me the document used a Mac as well so she was using Word for Mac.