I suspect that Flickr is adding your own photo views from when you were logged in to one views count, and not adding them to the other views count.

Flickr seems to treat views when logged in and views when logged out differently.  There's a discussion of this phenomenon here.

Is the difference in views approximately equal to the number of times you've viewed the photo when logged on?  If so, this could be the problem.  If not, perhaps you can post some follow-up information, so that I or someone else can explore the issue further.