Strange behaviour of private variable with OpenMP

Dear Intel users,

I have a strange behaviour with a PRIVATE variable. I'm using Intel Ifort 14.01

My program has many lines of code, so I report a snippet that summarize the situation. In the main I have an integer  global variable, a parallel region that sets that variabies, and a function ever in parallel region that uses the variable. If I define the variable PRIVATE, the code dies. If Ipass the same variable to a subroutine the code works fine, also if the results are not the same as serial code. This is the snippet that fails:

PROGRAM my_program

integer samplmin_newscal
integer samplmax, sampl0, deltaT
REAL(stnd),        DIMENSION(  :  ), allocatable :: t0

samplmax = some_value
sampl0 = some_value
 deltaT  = some_value

...allocate and set t0

$!OMP PARALLEL DO PRIVATE (i, samplmin_newscal)
DO i

  samplmin_newscal = some_value
  call my_subroutine()

END DO


contains

my_subroutine()

real to_tmp

DO  ij  = samplmax, samplmin_newscal, -1

 t0_tmp = t0(ij + sampl0)+deltaT  ! here the code dies with
                                  ! Subscript #1 of the array T0 has value 0 which
                                  ! is less than the lower bound of 1

END DO

END program my_program

This is the snippet that works well:

integer samplmin_newscal
integer samplmax, sampl0, deltaT
REAL(stnd),        DIMENSION(  :  ), allocatable :: t0

samplmax = some_value
sampl0 = some_value
 deltaT  = some_value

...allocate and set t0

$!OMP PARALLEL DO PRIVATE (i, samplmin_newscal)
DO i

  samplmin_newscal = some_value
  call my_subroutine(samplmin_newscal)

END DO


contains

my_subroutine(samplmin_newscal_local)

integer samplmin_newscal_local
real to_tmp

DO  ij  = samplmax, samplmin_newscal_local, -1

 t0_tmp = t0(ij + sampl0)+deltaT

END DO

END program my_program

No, I know thas if a variable is defined inside a module, must be declared THREADPRIVATE, but this is not the case. Why the private definitions seems to fail? 

Thanks in advance.