Gedit won't save a file on a VirtualBox share: Text file busy

I have a text file that I can change using other applications (for example openoffice). But when I try to change and save it using gedit, I am getting error from gedit: Could not save the file /media/sf_Ubuntu/BuildNotes.txt. Unexpected error: Error renaming temporary file: Text file busy the permission of BuildNotes.txt is as follow: -rwxrwx--- 1 root vboxsf 839 2012-10-26 12:08 BuildNotes.txt and user id is: m@m-Linux:/media/sf_Ubuntu$ id uid=1000(m) gid=1000(m) groups=4(adm),20(dialout),24(cdrom),46(plugdev),105(lpadmin),119(admin),122(sambashare),1000(m),1001(vboxsf) What is the problem and how I can fix it?