> On MacOSX 10.5, Sage 5.4.beta1 (with new GAP 4.5.6 spkg) I get
> (any idea what it could be? Endianness?)
> This is the only doctest failing on this platform.

> sage -t --long -force_lib
> "devel/sage/sage/schemes/elliptic_curves/padics.py"
> **********************************************************************
> File
> "/usr/local/src/sage/sage-5.4.beta1/devel/sage/sage/schemes/elliptic_curves /padics.py",
> line 799:
>     sage: for prec in range(2, max_prec):                 # long time
>           assert E.padic_height_via_multiply(Integer(5), prec)(P) == full
>   # long time
> Exception raised:
>     Traceback (most recent call last):
>       File "/usr/local/src/sage/sage-5.4.beta1/local/bin/ncadoctest.py",
> line 1231, in run_one_test
>         self.run_one_example(test, example, filename, compileflags)
>       File "/usr/local/src/sage/sage-5.4.beta1/local/bin/sagedoctest.py",
> line 38, in run_one_example
>         OrigDocTestRunner.run_one_example(self, test, example, filename,
> compileflags)
>       File "/usr/local/src/sage/sage-5.4.beta1/local/bin/ncadoctest.py",
> line 1172, in run_one_example
>         compileflags, 1) in test.globs
>       File "<doctest __main__.example_7[15]>", line 2, in <module>
>         assert E.padic_height_via_multiply(Integer(5), prec)(P) == full  
> # long time
>       File
> "/usr/local/src/sage/sage-5.4.beta1/local/lib/python/site-packages/sage/sch emes/elliptic_curves/padics.py",
> line 829, in padic_height_via_multiply
>         sigma = self.padic_sigma_truncated(p, N=adjusted_prec, E2=E2,
> lamb=lamb)
>       File
> "/usr/local/src/sage/sage-5.4.beta1/local/lib/python/site-packages/sage/sch emes/elliptic_curves/padics.py",
> line 1206, in padic_sigma_truncated
>         E2 = self.padic_E2(p, N-2, check_hypotheses=False)
>       File
> "/usr/local/src/sage/sage-5.4.beta1/local/lib/python/site-packages/sage/sch emes/elliptic_curves/padics.py",
> line 1425, in padic_E2
>         frob_p = self.matrix_of_frobenius(p, prec, check,
> check_hypotheses, algorithm).change_ring(Integers(p**prec))
>       File
> "/usr/local/src/sage/sage-5.4.beta1/local/lib/python/site-packages/sage/sch emes/elliptic_curves/padics.py",
> line 1565, in matrix_of_frobenius
>         Q, p, adjusted_prec, trace)
>       File
> "/usr/local/src/sage/sage-5.4.beta1/local/lib/python/site-packages/sage/sch emes/elliptic_curves/monsky_washnitzer.py",
> line 1651, in matrix_of_frobenius
>         F1_reduced = reduce_all(Q, p, F1_coeffs, offset)
>       File
> "/usr/local/src/sage/sage-5.4.beta1/local/lib/python/site-packages/sage/sch emes/elliptic_curves/monsky_washnitzer.py",
> line 1024, in reduce_all
>         exact_form = reduce_negative(Q, p, coeffs, offset, exact_form)
>       File
> "/usr/local/src/sage/sage-5.4.beta1/local/lib/python/site-packages/sage/sch emes/elliptic_curves/monsky_washnitzer.py",
> line 788, in reduce_negative
>         a[0] = base_ring(lift(a[0]) / (j+1))
>       File "parent.pyx", line 804, in
> sage.structure.parent.Parent.__call__ (sage/structure/parent.c:7228)
>       File "coerce_maps.pyx", line 82, in
> sage.structure.coerce_maps.DefaultConvertMap_unique._call_
> (sage/structure/coerce_maps.c:3547)
>       File "coerce_maps.pyx", line 77, in
> sage.structure.coerce_maps.DefaultConvertMap_unique._call_
> (sage/structure/coerce_maps.c:3449)
>       File
> "/usr/local/src/sage/sage-5.4.beta1/local/lib/python/site-packages/sage/rin gs/finite_rings/integer_mod_ring.py",
> line 925, in _element_constructor_
>         return integer_mod.IntegerMod(self, x)
>       File "integer_mod.pyx", line 177, in
> sage.rings.finite_rings.integer_mod.IntegerMod
> (sage/rings/finite_rings/integer_mod.c:3504)
>       File "integer_mod.pyx", line 1530, in
> sage.rings.finite_rings.integer_mod.IntegerMod_gmp.__init__
> (sage/rings/finite_rings/integer_mod.c:14993)
>       File "rational.pyx", line 2473, in
> sage.rings.rational.Rational.__mod__ (sage/rings/rational.c:19891)
>       File "integer.pyx", line 5485, in
> sage.rings.integer.Integer.inverse_mod (sage/rings/integer.c:32726)
>     ZeroDivisionError: Inverse does not exist.
> **********************************************************************
> 1 items had failures:
>    1 of  17 in __main__.example_7
> ***Test Failed*** 1 failures.
> For whitespace errors, see the file /Users/dima/.sage//tmp/padics_41488.py
>          [79.0 s]

> ----------------------------------------------------------------------
> The following tests failed:
>         sage -t --long -force_lib
> "devel/sage/sage/schemes/elliptic_curves/padics.py"
> Total time for all tests: 79.0 seconds