[Samba] Windows XP copies to Samba share slow on some folders

[PC]

I am experiencing a strange problem when copying large files to certain 
folders on a mounted Samba share (3.0.20b). I have also verfied the problem 
occurs with Samba 3.0.20 and 20a.

I can copy the file (560MB) to most folder (for example /home/pc/temp) with 
write speeds of about 7.5 - 10 MBytes / Sec and completes in a minute or two. 
However when I copy the file to a folder named /home/pc/Vault, the copy run 
extremly slow and takes about 50-60 minutes to complete.

The ownership/permission of the folders is the same (drwxrws---).

The problem only occurs for Windows to Samaba copies. I tested the copies 
using scp between two linux system and the copy rate are the same between all 
folders.

I looked in the smb.log file and did not see any errors or warnings.

Very odd...