These suggestions are based on Notes version 6.5. Below is what I can provide with the limited knowledge I have on the subject.
Have you checked the location setttings after opening Notes with the ID that doesn’t work? The bottom right of the screen should indicate the location such as Office (network). Right click on it and select Edit Current. There are several tabs to choose from. On the Basics tab check the Location Type. Select the correct one such as Local Area Network if that is your setup.
Check the remaining tabs and make your adjustments accordingly like the Servers tab to see if the correct Home/Mail Server is listed and the Mail tab to make sure the correct Domino domain is listed.
I wish you success
U said add the database file i.e .nsf file in the location where lotus notes is residing i.e under
Lotus->Data.Might be u have deleted that file from there.If i am not wrong this would work.
wish u all the best.