Exception during a loft building between two closed contours

Forum community reports an algorithmic bug during loft building between two close
contours.
The problem is checked (on all versions starting from 6.3.0 till 6.4).
It is reproducible on all versions.
thrusections tr 1 1 lw2 tw2
An exception was caught 004F56D4 : Standard_NoSuchObject:
BRepFill_CompatibleWires::SameNumberByPolarMethod : the wires must be closed
** Exception ** 004F56D4 : Standard_NoSuchObject:
BRepFill_CompatibleWires::SameNumberByPolarMethod : the wires must be closed

Script to reproduce bug.
=========================
restore lowWire1.brep lw1
restore lowWire2.brep lw2
restore topWire1.brep tw1
restore topWire2.brep tw2

thrusections tr 1 1 lw1 lw2 => OK
thrusections tr 1 1 tw1 tw2 => OK
thrusections tr 1 1 lw1 tw1 => KO
thrusections tr 1 1 lw1 tw2 => KO
thrusections tr 1 1 lw2 tw1 => KO
thrusections tr 1 1 lw2 tw2 => KO

Wires and picture are attached.
Also attached Word document - Attachment 1 (DOC) - with problem description from forum.