Lotus Domino Console closed unexpectedly

I have Lotus Domino 6.5.1 installed on a Windows 2003 standard server. The problem is that the Lotus Domino console shutdown (close) unexpectedly. In the event viewer the service LotusDominoServer (LotusDominoData) is stopped. When I start the service the console appears and works por a while until it shutdown again. What can I do?

Subject: Lotus Domino Console closed unexpectedly

I have the same problem with two different servers running under Windows 2k Server and Domino 6.0.3. Log seems to have no information about the problem (system and domino).

Anybody knows how to fix this?