I'm using WP Photo Plus on my website and like it. I'm up to date on the version. I ran into one problem. On some of my captions I have quote marks in the text. If I hover the mouse over the thumbnail they display fine. If I click on the thumbnail to enlarge the picture, all quote marks change to ""e" which isn't the end of the world but it just looks sloppy.
My site is http://www.billthompson.us - check the photo gallery under Brighton Sound and photo #5 (The Brighton coffin). hover over the photo and note the quote marks in the text. Then click the photo to enlarge it and again look at the text, note what happens to the quote marks.