1. Perhaps the attitude of Conrad to Dostoevsky is worthy to note in context of this thread, since it reflects on some Polish-Russian relations.
Dostoevsky's deeply prejudiced treatment of Poles and his virulent opposition to Poland's historical traditions, combined with Conrad's familial and personal experience of Russian oppression (…) amply explain both Conrad's hatred of him and his painful "sense of Russia as a source of evil."
There was no name in literature that Conrad detested more than that of Dostoevsky
From: The life and the art: a study of Conrad's "Under western eyes" By Keith Carabine
Yet his novel "Under Western Eyes" bears the patent similarity to Dostoevsky's "Crime and Punishment" and is viewed as Conrad's response to the themes explored in the latter. On the other hand Conrad sympathizes with ordinary Russians, which are main heroes of his novel.
2. Poles were hostile to idea of Pan-Slavism, considering it a continuation of Russian imperialism. For some reason some Slavs, including some Russians, considered Poles the traitors to the idea of the "brotherly love".
Again Joseph Conrad, in Notes on Life and Letters.:
"...between Polonism and Slavonism there is not so much hatred as a complete and ineradicable incompatibility." ...Conrad argues that "nothing is more foreign than what in the literary world is called Slavonism to his individual sensibility and the whole Polish mentality"
- from wikipedia, Pan-Slavism
During Poland's communist era the USSR used Pan-Slavism as propaganda tool to justify its control over the country. The issue of the Pan-Slavism was not part of the mainstream political agenda, and is widely seen as an ideology of Russian imperialism.
3. Stalin's famous statement "The introduction of communism in Poland would be similar to the imposition of the saddle on a cow" demonstrates a continuation of justifiable Russian distrust of Poles.