unexplained exception disappears with /check:pointer or other strange conditions

[TheClassic]

(I'm using 10.1.4161.2005)
I have a Fortran library that is called from VC++ and calls several C++ methods. I am changing the interface declarations for calls out to C++ to use ISO_C_BINDING. After making these changes, when running in release an exception occurs in the Fortran code. I tracked it down (by debugging the C++ code) and it seems to occur immediately after returning from the C++ function that is called by my Fortran code. I have found that putting a WRITE statement before and after the function call eliminates the exception. Also setting Omit Frame Pointers to No or using /check:pointer eliminates the problem. The data passed to and from the C++ seems valid.
I have pasted the Fortran interface declaration and C++ function declaration for the function that I am calling in the Fortran code. I can't find any reason why this exception is occuring or why I can make it dissapear using the methods I listed. My understanding of /check:pointer is that it should report a problem so that it can be resolved, not eliminate the problem.

Before:
interface
Integer function PointvectorLOS
& [C, ALIAS:'_PointVectorLOS']
& (Sourcept,Rayvector,MaxHits,NumHits,
& HitIdlist,HitTypelist,Entrypt,Exitpt,EntryNormal,
& ExitNormal, bSkipRubble)

real Sourcept [REFERENCE]
real Rayvector [REFERENCE]
integer MaxHits [VALUE]
integer NumHits [REFERENCE]
integer HitIdlist [REFERENCE]
integer HitTypelist [REFERENCE]
real Entrypt [REFERENCE]
real Exitpt [REFERENCE]
real EntryNormal [REFERENCE]
real ExitNormal [REFERENCE]
logical bSkipRubble [VALUE]

end function PointvectorLOS
end interface

After:
interface
Integer(c_int) function PointvectorLOS
& (Sourcept,Rayvector,MaxHits,NumHits,
& HitIdlist,HitTypelist,Entrypt,Exitpt,EntryNormal,
& ExitNormal, bSkipRubble)
& bind(C,name='PointVectorLOS')
use ISO_C_BINDING

real(c_float) :: Sourcept
real(c_float) :: Rayvector
integer(c_int), VALUE :: MaxHits
integer(c_int) :: NumHits
integer(c_int) :: HitIdlist
integer(c_int) :: HitTypelist
real(c_float) :: Entrypt
real(c_float) :: Exitpt
real(c_float) :: EntryNormal
real(c_float) :: ExitNormal
integer(c_int), VALUE :: bSkipRubble

end function PointvectorLOS
end interface

(I have made the appropriate changes for the change of bSkipRubble from logical to integer.)

C++ declaration:
int PointVectorLOS( float *SourcePt, float *vect, int maxhits, int *NumHits, int *HitIDList,
int *ibHitTypeList, float *EntryPt, float *ExitPt, float *EntryNormal, float *ExitNormal, int bSkipRubble);