[Samba] can't save 0 size file in samba 2.0.7

[liu jack]

Dear all:
     
    Now I use samba 2.0.7 for my file server,but I encounter some odd 
questions,hope to get your help.
   First question,if I creat one new NULL txt file in samba share folder 
whose filesystem is FAT,and I open the file in notepad in windows,type some 
characters,and save the file,but error says "refuse to access".and if the 
txt file has content,even if one character,there is no the problem.And the 
problem doesn't appear in ext2 filesystem folder.
    Second question,if I have changed the smb.conf,for example,I deleted 
one share folder for user1,but if user1 had opened the share,then he can 
use the share folder yet unless I kill the smbd process.

    and I have solve another odd problem, if I create one new folder or 
copy folders to the samba share,there will be one error:duplicated name.By 
mount -o quiet,I solved the problem.
    
    Below is my samba config.

    [global]
         netbios name = jack
         workgroup = workgroup
         server string =
         security = user
         encrypt passwords = yes
         socket options = TCP_NODELAY SO_RCVBUF=8192 SO_SNDBUF=8192
         name resolve order = wins lmhosts bcast
         wins support = yes
         dns proxy = no
         deadtime = 5

    Thanks 
    Jack