Photo selection and targeting in Lightroom is indeed one of it's trickier aspects, in my opinion as well. I still make mistakes even after a half-decade of frequent use.
When exporting, it targets all selected photos in the filmstrip, regardless of whether you're viewing grid or loupe, whereas when deleting, and some other ops, it only targets the most-selected photo (when in loupe view).
Not sure what to say, except when exporting - double check the number of photos being exported - it gives the number at top of export dialog box.
Thanks guys. Keeping an eye on the bottom bar is a good tip. I do a lot of spray-and-pray type shooting, so I often come back from a shoot with 2,000+ images, and therefore I use the application like a crackhead with ADHD. I guess it is a matter of just double-checking everything.
I am so pleased to read your post and realize I'm not the only one that gets tripped up by this! I've bee using LR extensively for more than two years now and even today, just now, I wanted to export ONE file, and the highlighting onscreen appeared to indicate I've selected one file, but turned out it was dozens of files. Now... when I'm simply exporting copies of files to another folder it's not a dangerous situation. BUT! It is very dangerous if one wishes to delete a file or several files and you think those are the only files you're deleting. Many, many times I have caught this in time, fortunately. To me this is one example of how the experience of software designers do not well understand how the end user will understand a program. Professional photographers are very specific with everything they do and don't want a program tripping them up continually. This obvious confusion over which files are actually "selected" needs cleared up.
I read the responses to your post and find them dissatisfying. Please, Adobe, test your software with actual working photographers and not just Adobe engineers who may also happen to be amateur photographers.