It's almost definitely a lie. I think what's going on is that it's tracking the 0856 upgraded files (it seems as though you have done incremental patches since 0856). So basically it thinks that the 0874 files you are using are still 0856. As to the size, that is totally wrong, and I have seen that happen with programs before; it's not really anything to worry about.
...but just in case, the above poster has an excellent suggestion ^
It is a lie. If you ever reinstall BF2/PR you can remove all of them from there first, but that would only be for aesthetically reasons, it won't actually change anything.