If you have a newer firmware, you need additional equipment (passme2) to make it compatible (no matter what product you decide on). Yes, an older ds would be one solution to that issue.
I'm assuming you can't return/exchange your mk3 2006?? There is another possibility that the mk3 2006 is defective, but it appears that the primary issue is an incompatible firmware, based on the pictochat test results...
BruceG
EDIT: For your particular product, either the .nds file or the .gba menu file should work...