This could be related to problem #547. When using a polyhedra as a geometry element interaction points are reported that are outside the defined World. This occurs if the inner radius is defined as 0.0*cm. Using a non-zero value I got down to rInner[0] = 10.*nm without the bug being repoduced. RH8.0, G4.6.0, CLHEP1.8.2
The fix to problem #547 was introduced in patch-01 to release 6.0 (i.e. 6.0.p01). Did you try applying the patch ?
Karl Hauschil <hauschil@csnsm.in2p3.fr> wrote: > > The patch 6.0.p01 seems to have fixed this problem.