Win 7 64 bit
Short description of error
Mesh called Array is using array modifier with start cap option, all vertices of it belong to "Mask" vgroup. Some vertices of Start Cap mesh belong to "Bevel" vgroup.
When I choose "Bevel" group in Bevel modifier, vertices that are not in this group somehow merging with "Mask" group of Array mesh.
Exact steps for others to reproduce the error
Open file, choose "Bevel" vgroup in Bevel modifier -> see how another mesh is masking
PS. Workaround is to create another empty vgroup in the Start cap mesh and place it before "Bevel" group