In Windows XP, when I clicked "Properties" on a folder, it said
Size: 788 MB (826,867,591 bytes)
Size on disk: 806 MB (845,590,528 bytes)
Contains: 8,772 Files, 0 Folders
When I entered the folder, the bottom left hand corner said
9,512 objects
and when I selected all the items and did "Properties", it said
2,970 Files, 0 Folders
Size: 452 MB (474,082,998 bytes)
Size on disk: 457 MB (479,973,376 bytes)
I don't think any of the files are hidden - the only thing I can think of is that the folder hierarchy has gotton pretty deep at that stage.
I think the 9512 objects is the correct figure, based on running the following in git bash:
$ find . | wc
9513 9513 785977