Based on the check done on F-12 system, your package owns directories owned by filesystem. 
This is not allowed by Fedora policies. 

See http://fedoraproject.org/wiki/Packaging/Guidelines#File_and_Directory_Ownership 
for details.

(Sub)package gtk-murrine-engine:
/usr/share/themes

This is autogenerated bugzilla, I'm sorry if the problem is already fixed or reported. Additionally I apologize if that directory ownership was requested earlier by some bugzilla (some directories were probably added into filesystem package later, so your package should no longer own that directory).