single instance not working

[new_to_smplayer]

recently started using SMPlayer (0.6.9) on Windows 7 32bit
fantastic program, but
single instance does not work
can not work out why searched forum and net and no fix
as much as i would like to continue using SMPlayer will have to go back to VLC if can not resolve

any help or suggestions as to how to sort this would be greatly appreciated

cheers

hopeful