This bird shoved up in the hotel garden close to the airport in Medellin, July 2008. I never managed to see the face well. From the pictures it is possible to see the reddish at the crown and wings. The breast is and throat looks all dark grey. The bird seems to be a Spinetail, and the best alternatives are Azara's, Silvery-throated. Ash-browed or Slaty Spinetail. The tail is unusually long and Tit-Spinetail shaped (probably because the tail is worn), and could indicate a Silvery-throated or Azara's Spinetail (the somewhat reddish tail seems to indicate the latter). The tail is probably to long for both Ash-browed and Slaty Spinetail, but the coloration of the breast could indicate that this is Salty Spinetail (although the length and colour of the tail don't fit with this species).
It looks like this is Azara's Spinetail, also from one comment I have received.