Need help with cover size filter

Hi,i want to filter out the covers that shows in the example.
they are 21 kb,but if i use this line:"%_cover_size%" GREATER 21504 AND "%_cover_size%" LESS 21580
the i get covers that are 21kb but not the one`s that shows in the example while they are 21kb too
how is this possible?


Sorry but your example picture is not readable.

Please read again ...
Search on cover size?
... did you follow the examples?

Note that the dimension in KB is always a rounded value.