Here is what happened in the Deathly Hallows, just after Harry accidentally mentioned "Voldemort".
"The name's Taboo!" Ron bellowed, leaping to his feet as a loud crack sounded outside the tent. "I told you, Harry, I told you, we can't say it anymore. We've got to put the protection back around us quickly. It's how they find "
But Ron stopped talking, and Harry knew why. The Sneakoscope on the table had lit up and begun to spin; they could hear voices coming nearer and nearer: rough, excited voices.
And once Harry, Ron and Hermione are captured, the Snatchers and Greyback search the tent and take possession of the sword of Gryffindor.
"Hey!" came a shout from inside the tent. "Look at this. Greyback!"
A dark figure came bustling toward them, and Harry saw a glint of silver to the light of their wands. They had found Gryffindor's sword.
Given that this happened while they were comfortably settled in one place, having a conversation, after listening to an episode of "Potterwatch", and given how careful they had been up to then about security, it strikes to me as very odd that they had no protective enchantments in place at this point.
Does anyone else find it unrealistic, that the one time they are lax about security, Harry accidentally fell for the Taboo? Or is there any other explanation for this? Do the protective enchantments break once the Taboo comes into play, and was Ron pointing out that now that the enchantments must have broken, they had to redo the spells quickly before the Snatchers got there?