[TokuChris]

I had always assumed that they had lost the Titanium Ranger suit. After Disney bought Power Rangers from Saban, they were planning to end the series at the end of "Wild Force", hence the title of the finale, "The End of the Power Rangers". They reportedly cleaned house, throwing away and auctioning off a LOT of old stuff.

The Green Ranger suit from MMPR had to be "re-created" for the cameo in Dino Thunder, while the Zeo suit was the one from Forever Red (I believe), and the White Ranger suit was a used Sentai stunt-suit (hence the armor "falling apart"). I could be wrong but that's what I gathered from Doug Sloan's comments back in the day.