mesh/tet and insert/pack

Hi. I want to use mesh/tet and insert/pack features.
I use in.insert_pack example file as basic for my simulation.
But I get an error when I use own insertion region geometry file instead of test.vtk:

LIGGGHTS 1.4.1 based on lammps-10Mar10
Created orthogonal box = (-1 -1 -1) to (1 6 2)
1 by 4 by 1 processor grid
Fix particledistribution/discrete (id pdd1): distribution based on mass%:
pts1: d=5.000000e-02 (max. bounding sphere) mass%=30.000000%
pts2: d=3.000000e-02 (max. bounding sphere) mass%=70.000000%
Fix particledistribution/discrete (id pdd1): distribution based on number%:
pts1: d=5.000000e-02 (max. bounding sphere) number%=8.472803%
pts2: d=3.000000e-02 (max. bounding sphere) number%=91.527197%
Note: Skipping empty line in VTK mesh file
Note: Skipping empty line in VTK mesh file
Note: Skipping empty line in VTK mesh file
0 atoms in group nve_group
INFO: Resetting random generator for region mesh
FixInsertPack: Volume of insertion region: 0.000000
FixInsertPack: Volume of insertion region: 0.000000
ERROR: Illegal fix insert/pack command, would insert 0 particles per insertion step
FixInsertPack: Volume of insertion region: 0.000000
FixInsertPack: Volume of insertion region: 0.000000

Is it something wrong with my vtk file?
I attach my vtk file and modified in.insert_pack file.