Sasha:
Are there any sources in Poland that provide with "German version" evidence of the massacre?
Russia has admitted to the crime, now they say it was Poland's fault for killing Soviets. This is not true but it's another scape goat to stall the case. Taking the step backwards and refusing to release the files held within Russia cannot last forever.
I also feel that the Russia people that know the full history want to deal with the past and take responsibility. Putin on the other hand is well aware that this will open the door to all the deaths that took place when Soviets attacked eastern Poland on Sept. 17,1939 and continued even as Poland was an allie. It put's Russia and Germany on the same table.
Growing up in the USA I never had to deal with secrets and hiding history. My Dad would not speak of his past in Poland or Siberia. Russia, Poland and Germany were just country's in Europe that we came from. To study from the outside/in must be so differant?