Cinemateca Uruguaya has provided me the following information (sorry if certain titles of Lem's books are por translations of my spanish versions):
-Der Schweigende Stern [1959], german film upon "The astronauts"
- Proffesor Zazul [1962], polish TV film; episode from Tichy's voyages.
- Przekladaniek [1968], Wajda film for polish TV (can anybody identify the source Lem's text?)
- Ikaria-XBI [1968-71], czech film partially based upon Nebula Magallanica.
- Solaris [1971], the well known Tarkowsky masterpiece.
- Test Pilota Pirxa [1979], russian-polish production from Pirx adventures, directed by Marek Piestrak.
- Szpital przemienienia [1979], Edward Zebrowski film based upon Hospital de la transfiguración.
- Un si joli village [1978], frencho film, directed by Etienne Perier, upon The Investigation.
-Victim of brain (sorry about crude translation), dutch film, 1988, dir. Piet Hoenderos, aparently based upon Peace on earth.
- Marianengraben [1994], german film, dir. Achim Bornhak, screenplay by Lem & Mathias Dinter.
Best regards,
Carlos