Photoshop Elements :: Creating 11x14 Poster Using Multiple Photos?

I have created numerous posters in the past on an older version of PS.  I am currently using Elements 11.  I need to make 13 different posters for a team party by Thursday evening.  I want to make 11x14 posters using a photo in the background, and add 4 small ones to it.    I put hours into creating these posters, and when I had them printed, the large photo was fine, but the smaller ones are very blurry.  I have never had this problem when I have done these in the past......I could understand the big photo getting pixely, but the small ones are usually very sharp.