Hey there tempers...
well i have a method to play MGSPW on your d3 without any problems...
1. You will need this pack
MGSPW TOOLS
2. Extract and put the content on the root of your MS
3.Before start playing you will need to start the 1st tool "MGSPW D3FIX"
4. Play ....
5. when you finish your gameplay , start the second tool "MGSNever"
EDIT: *THE GAME DOESNT WORK WITH A PREVIOUS PATCH *
*you need to do this wvery time you play
*ITS BETTER THAN DOWNGRADING ^^