Hi, Thanks for the response. I can't share my site url with you because it is running on my laptop at the moment. :)
I've been continuing to look at this, and I think I've figured it out. It appears this is not a problem with Easy FancyBox. NextGen Gallery is hard-coded to set the anchor tag title attribute to the description field for each photo. It does not use the title/alttext fields for each photo.
What I ended up doing is making a copy of wp-content\plugins\nextgen-gallery\view\gallery.php file, naming it gallery-title.php and copying it into wp-content\themes\twentyten\nggallery folder. I updated the php code to set title to the actual title/alttext field of the image, and now FancyBox correctly displays the title with each picture in the light box.
In my shortcode on the post/page where I display the gallery I include template=title which tells NextGen Gallery to use the new modified gallery-title.php file, like this: [nggallery id=35 template=title].
I think this is the correct way to do this, though I wasn't able to find this in the documentation. If there is another/better way to do this, maybe someone can share some tips.