I'm using build 7229 and I had this problem with 7100 also.
If I'm trying to move / delete a big file (over 700MB) i'm getting the following window:
just calculating forever.
the hard disk light indicator ain't flashing.
it's working fine with XP.
I scanned my disk for errors and it's fine.
tried to delete / move using unlocker and cmd (DOS) and it's the same. with both of them nothing happens.