Version:           3.1 (using KDE KDE 3.1.4)
Installed from:    RedHat RPMs
OS:          Linux

The folder size shown in the status bar at the bottom of the screen and the folder properties box should show the how much they've counted up to so far, not zero or calculating..., formated something like:
'Open Directory Name'>=1,024 items (>=67,108,864 Bytes Bytes Tolal) >= 15 SubDirectories
and when it finishes that part something like:
'Open Directory Name' Contains 4,096 items (268,435,456 Bytes) and 60 SubDirectories 
Then start calculating the subdirectories (Do this last for sure)
'Open Directory Name' Contains 4,096 items (268,435,456 Bytes) and 60 SubDirectories (>=1,024 items and >=2,048 Bytes)
Finally
'Open Directory Name' Contains 4,096 items (268,435,456 Bytes) and 60 SubDirectories (10,240 items and 20,480 Bytes)
Try not to use so much CPU when doing this last part or make it optional or even don't include it(only for the status bar, not the properties box).