The products affected by the bug are Domino Server 5.x, Domino Server 4.6x, Domino 4.5.7, Domino Server 4.5.6, Notes Client 5.x, Notes Client 4.6x, Notes Client 4.5.7 and Notes Client 4.5.6.
CNN: Y2K glitch can crash some Domino servers, Notes clients