Hi, I haven't encountered any problems so far (apart from the two error messages for a scipy.test(10), see below). (I think they were reported already a while ago). I had another look at it and to me it seems that the multiplication of a instance of the polynomial class is the culprit, p = scipy.poly1d([1,2,3]) p(0.5) # fine 2.0*p(0.5) # fine 2*p # KeyError (2*p)(0.5) # KeyError The last two lines work with python 2.2 (scipy.__version__: '0.2.0_alpha_200.4160') whereas with python 2.3 (scipy.__version__, '0.2.0_alpha_210.4098') they fail. Hmm, addition seems to be broken as well: p1 = scipy.poly1d([1,2,3]) p2 = scipy.poly1d([1,2,3]) p=p1+p2 # KeyError However I did not manage to find a fix for this. Arnd ====================================================================== ERROR: check_chebyc (test_basic.test_chebyc) ---------------------------------------------------------------------- Traceback (most recent call last): File "/home/python/PYTHON/lib/python2.3/site-packages/scipy/special/tests/test_basic.py", line 214, in check_chebyc chebc = chebyc(1)(.2) File "/home/python/PYTHON/lib/python2.3/site-packages/scipy/special/orthogonal.py", line 398, in chebyc p = p * 2.0/p(2) File "/home/python/PYTHON/lib/python2.3/site-packages/scipy_base/polynomial.py", line 445, in __getattr__ raise KeyError KeyError ====================================================================== ERROR: check_chebys (test_basic.test_chebys) ---------------------------------------------------------------------- Traceback (most recent call last): File "/home/python/PYTHON/lib/python2.3/site-packages/scipy/special/tests/test_basic.py", line 220, in check_chebys chebs = chebys(1)(.2) File "/home/python/PYTHON/lib/python2.3/site-packages/scipy/special/orthogonal.py", line 429, in chebys p = p * (n+1.0)/p(2) File "/home/python/PYTHON/lib/python2.3/site-packages/scipy_base/polynomial.py", line 445, in __getattr__ raise KeyError KeyError -