Cannot read an image with imread() on Mac

[conahorse]

Hi, I'm using octave 3.2.4 on a Mac with Snow Leopard. When I try to read an 
image in the current directory I do something like:

I = imread('cell.jpg')

but an error occurs:

Assertion failed: (semaphore_info != (SemaphoreInfo *) NULL), function 
LockSemaphoreInfo, file magick/semaphore.c, line 525.
panic: Abort trap -- stopping myself...

What am I missing?
I am a newbie with octave, I installed a new version of libpng (now 1.4.5) and 
recompiled octave since before this error I got an error saying the old library 
was missing