Cannot install nike+ utility on my mac anymore

Hi

I have been using the Nike+ utility on my mac for several months without any major problems.
Suddenly, now I can't install it anymore.
First the version I had installed did not appear when I placed my nike usb stick in the computer. Then I installed the program again and it installed success. However the program is not under applications or utilities and it still does not start up when I place the usb stick in the computer.


Any ideas?