Distfile size mismatch for ImageMagick portupgrade

[Mike Clarke]

Upgrading ImageMagick from 6.3.6.9 to 6.4.0.11 fails after downloading 
the distfile with "size mismatch: expected 5837175, actual 5836089".

I don't see anything relevant in UPDATING or on the Freshports site. 
I've run pkgdb -u and downloaded a fresh copy 
of /usr/ports/graphics/ImageMagick but still get the problem.

Is this a general problem or have I overlooked something?

-- 
Mike Clarke