Malwarebytes disappearing act?

[Altaira]

I've been using the free software version for a while now without any problems. The other day, I clicked on the icon on my desktop and nothing happened. After clicking several more times with no response, I brought up the file and it was empty.

I'm the only one that has access to the computer and was just wondering how this could have happened. I reinstalled the software and ran a quick and full scan and there were no infections and Norton Antivirus 2012 found nothing as well.

Any input would be greatly appreciated.

TIA

[David H. Lipman]

what happens if you go to; RUN and launch MBAM.EXE manually ?