I found this problem both on 1.1.5 and also on 2.0.3 with Windows XP Home SP2.
1 - Run the macro hereunder, choose a file. 
2 - Then try to rename the directory of the file: rejected "resource used by another 
user or program".
3 - Run again the macro, choose a file in another directory.
4 - Try to rename this last directory: rejected. Try to rename the former directory: 
now it is accepted.
5 - the only way to unlock is to close OOo.

Sub testFilePicker
fp = createUnoService("com.sun.star.ui.dialogs.FilePicker")
fp.appendFilter("All", "*")
fp.CurrentFilter = "All"
fp.Title = "Choose a file"
if fp.execute = 1 then
  lesFichiers() = fp.Files
  MsgBox(lesFichiers(0) )  
end if
fp.dispose
End Sub