BOAC,
at the the Smolensk forum there were some question rised regarding the position of the far beacon and the difference between data on the approach charts available so far and Google Earth data. I think the problem is solved.
From the "101" crew point of view those 160 m (or maybe 260, the chart is unreadable) were meaningless.
It also means, that when ATC is giving the crew the "6 km" distance, there is a few hundred meters error, just like for 4/3/2 km, which rises a few questions about how the RSP-10 system at Smolensk was calibrated and (in?)accurate. Just that.
The system was tested a few days after the crash, but so far really nothing was published about it.
Arrakis