The changelog for libmpg123-dev says:
mpg123 (1.13.7-3) experimental; urgency=low
  * Enable LFS aliases, attempt to fix FTBFS on kfreebsd-i386.
  * Drop static library.
  * Improve ARM CPUs optimizations.
 -- Alessio Treglia <alessio@debian.org>  Thu, 29 Mar 2012 14:13:02
    +0200
Why has the static library been dropped?
urs