Errors on cyl-triax test example

Dear all,
   when I run the cal-triax test example, there are some errors :
  "---------------------------------------------------------------------------
NameError Traceback (most recent call last)
/usr/bin/woo in <module>()
      7 if __name__ == '__main__':
      8 sys.exit(
----> 9 load_entry_point('woo==0.99-3584-21-openmp-ubuntu14.04.1', 'console_scripts', 'woo')()
     10 )

/usr/lib/python2.7/dist-packages/wooMain.pyc in main(sysArgv)
    317 ### otherwise Qt4 might crash at this point
    318 #import woo.qt # this handles all Qt imports
--> 319 ipythonSession(opts,qt4=True,qapp=woo.qt.wooQApp,qtConsole=woo.qt.useQtConsole)
    320 #woo.master.exitNoBacktrace()
    321 # uninstall crash handlers

/usr/lib/python2.7/dist-packages/wooMain.pyc in ipythonSession(opts, qt4, qapp, qtConsole)
    370 sys.stderr.write("Using preprocessor "+arg0+'\n')
    371 import woo.batch
--> 372 woo.master.scene=woo.batch.runPreprocessor(obj,arg0)
    373 woo.master.scene.saveTmp()
    374 else:

/usr/lib/python2.7/dist-packages/woo/batch.pyc in runPreprocessor(pre, preFile)
    584
    585 # just run preprocessor in this case
--> 586 if not inBatch(): return pre()
    587
    588 import os

/usr/lib/python2.7/dist-packages/woo/pre/cylTriax.pyc in __call__(self)
     67 def __call__(self):
     68 # preprocessor builds the simulation when called
---> 69 return prepareCylTriax(self)
     70
     71

/usr/lib/python2.7/dist-packages/woo/pre/cylTriax.pyc in prepareCylTriax(pre)
    191 mass=nodeMass,inertia=nodeInertia*Vector3(1,1,1),
    192 suppMat=S.lab.suppMat,sideMat=S.lab.memMat,
--> 193 sideThick=pre.memThick,
    194 )
    195 S.lab.cylNodes=nodes

/usr/lib/python2.7/dist-packages/woo/pre/cylTriax.pyc in mkFacetCyl(aabb, cylDiv, suppMat, sideMat, suppMask, sideMask, suppBlock, sideBlock, sideThick, mass, inertia)
    121 return ret
    122 for i in range(0,len(nnn)-1):
--> 123 retParticles+=mkAround(nnn[i],nnn[i+1],mask=sideMask,mat=sideMat,halfThick=.5*sideThick)
    124 for p in retParticles: p.shape.wire=True
    125 import itertools

/usr/lib/python2.7/dist-packages/woo/pre/cylTriax.pyc in mkAround(nnAC, nnBD, mask, mat, halfThick)
    116 for i in range(len(nnAC)):
    117 A,B,C,D=nnAC[i],nnBD[i],nnAC[(i+1)%len(nnAC)],nnBD[(i+1)%len(nnBD)]
--> 118 ret+=[woo.dem.Particle(material=mat,shape=Membrane(nodes=fNodes,halfThick=halfThick),mask=mask) for fNodes in ((A,B,D),(A,D,C))]
    119 for n in (A,B,D): n.dem.addParRef(ret[-2])
    120 for n in (A,D,C): n.dem.addParRef(ret[-1])

NameError: global name 'Membrane' is not defined

The version of Woo is "0.99+3584+21~openmp~ubuntu14.04.1".

Thanks a lot!
Best regard,
Henry