Qr Codes & Changing Passcodes

I uploaded my cvs file (with passcodes listed),  but on some (but not all) of the entries, it added 2 extra characters at the end of the passcode.   I made sure any previous uploads were deleted, so I'm not sure what's happening.

EDIT: I figured it out, but now have a new issue.  I had cleared any previous uploads from that same page, but still had them in a different gallery that I had set up to test everything.  So I'm good now, BUT I always make the passcode the student's firstnamelastname.  So, short of deleting the previous year's gallery page, is there anything that can be done to allow the same passcode to be used each year?   

I don't find it a good idea to have the same password being used multiple times. I'll make a note to put some thought into it. 

Just my opinion, having the passcodes "firstnamelastname" seems fairly insecure. Be easy for other people to guess. 

Oh yes, it's definitely insecure.  When I first starting photographing this school,  I didn't even use passcodes and each class had their own gallery, so you could see other people's photos.  At this point, the school hasn't been concerned about this at all.  I switched to passcoding each photo a few years back, but making sure each kid actually gives their parents the piece of paper with the passcode on it seems risky.  I have three kids of my own and there are so many things that don't make it home.  haha.  So the firstnamelastname is a super easy way to pass along that information, while maintaining a small level of privacy.