We have migrated site from MOSS to Sharepoint 2013 by using OOTB Export\Import APIs. Everything is working fine apart from user security. I can see that all the users are migrated to the destination site but when I check their permission it tells that no permission is granted to the user.
I tried adding the same user again from the gui and the security for that particular user started working. I am attaching screenshots of both the user(one which was not working and the one that i added again).
same user is shown twice
This is the user which was migrated OOTB
This is the user that I added through GUI