"numpy.dtype has the wrong size, try recompiling"

[troubled]

Using numpy 1.6.2, I downloaded installers for guiqwt from the following:

http://www.lfd.uci.edu/~gohlke/pythonlibs/#guiqwt

However, I keep getting the error"
File "C:\Python27_64\lib\site-packages\guiqwt\image.py", line 176, in
<module>
from guiqwt.histogram2d import histogram2d, histogram2d_func
File "numpy.pxd", line 155, in init histogram2d (src\histogram2d.c:4758)
ValueError: numpy.dtype has the wrong size, try recompiling

Everything is 64-bit and PyQwt works fine for me. I have no troubles with
numpy at all except when trying to use this package. Can anyone help as to
why am I getting this error?

Thank you.