hi
sure i could dig up some diagrams, but each solution is symptom-driven, so it is best to find out why the reset is happening and then apply the simplest solution. Did you try the extra filter caps on the Diecimila? If that works, tutorial-wise it would be just a matter of saying add 220Uf or something to the +5/GND pins. I am almost certain that that is why it is happening, and I still have that bag of grommets.
If you really want to get to the bottom of things to discover why your Diecimila is more sensitive to noise than earlier versions, then the scope is the ticket. I can only think of three ways that the reset could be happening: via the reset line, a brownout on the power supply line, or within the code somewhere. The scope will tell you if it's one of the first two. From that you can suggest a tutorial workaround.
D