What specification is the PC you are trying to run it on?, what operating system are you using and is there anything else happening (sound etc) in the background.
It may be that the Emulator is not getting focus (trying hitting ALT and TAB together) or that your OS or PC architecture isn't suitable for the emulator.
There's also a more recent version available you could try which you can grab by visiting the main page of this site and browsing the Snes emu's.