(meteorobs) New Mexico Fireball - Composition? - Ice?

[Thomas Ashcraft]

I am trying to figure out why the September 13, 2007 0920 UT fireball 
over New Mexico made such an insubstantial forward scatter reception as 
received by my system. I consider this an anomaly. This fireball made 
only a weak signal at best.  You can hear it sort of "singing" lightly 
in the movie if you play it loud enough. Radio frequency was 83.250 MHz, 
tv channel 6 video carrier wave.

I am wondering if this particular fireball was merely made of ice or was 
possibly a little comet or comet core?

Chart and movie below:
http://www.heliotown.com/Fireball_Sep_13_2007_Ashcraft.html

Am still analyzing.

Thomas Ashcraft