Ok, be sure you are able to view Japanese text 
here for a min...  I beleive that says 置きセルA
下　(oki seru A shita-- I *hate* romaji!!), and 
I think that means that there is another layer 
or something behind the A layer every other 
cel.  If you say that the cel itself is kinda 
strange, maybe that's why.  I hope that's 
accurate enough for you!!  =)

Rekka