Unfortunately, yes. The grib api can't handle numpy integers.
```
>>> g = gribapi.grib_new_from_samples("GRIB2")
>>> gribapi.grib_set_long(g, "scaledValueOfFirstFixedSurface", 1)
>>> gribapi.grib_set_long(g, "scaledValueOfFirstFixedSurface", np.int32(1))
Traceback (most recent call last):
  File "<stdin>", line 1, in <module>
  File "/home/h05/itbb/fcm/iris/sci/lib/python2.7/site-packages/gribapi.py", line 59, in modified
    "Parameter '%s' should be type %s" % (name, " or ".join([t.__name__ for t in allowed_types]))
AssertionError: Parameter 'value' should be type int or long or float or str
```