Train reserves the path to go in the station. Before it arrives on the reserved lane I extended the station. The train reserves new path and the station lane with the older path remains reserved. Changing the signal type does not help. The only solution I found was to delete the station lane and rebuild it.
Thanks for this. There's been no activity on this for some time, and as it stands, it doesn't look likely that it will go any further. I'm closing it as we try to keep the issue count low for OpenTTD, it helps us focus on things that are important and fun. Feel free to discuss in irc or request re-opening if you disagree. Thanks for contributing!