I had a 2004 3di which popped on 200'. I bought it on 180'.
So NO, it is not full-proof.
But then exactly when the changes were made (2003 or 2004) is difficult to know. It is safe to say though that the 2005 model is post the changes.
Many would agree though, that you can buy a 3di, and by taking the right precautions, you can still have a long and happy relationship with her.
In fact, if I had the chance again, I would still be tempted to buy the 3di. Install the EGT, just to see how how well / easily the engine can managed to remain outside of the danger zone.
So why buy a 3di? Because you get a truck that achieves almost 10km per liter. And it still has more than enough power to do what Patrols do best.
There is tons of info on the 3di on this forum, but if you want to know exactly what changed in 2004 (or 2003?) and why it is safer (and how much safer), the Aussie forum site may have that, although some experts on this forum can also give you a rundown.