Installing plugin redirects to home page

Hi All,

I seem to have a strange issue, when I try install a plugin via upload method it redirects to the home page of the site, I have tried a few times and the same issue, I can upload via ftp but I am unsure as to why this wont work. The uploads and plugins folder has been chmod to 777. I have a another install on another server and it works fine there. Any assistance is appreciated.