Migration Incompleted. Only on 2 browsers.

[joebordes]

I'd say it is a problem with the vtigerversion.php file. This file is updated to be in sync with the database version but if the web user doesn't have permission to write on the file then the database says one thing and the code another. it is kind of strange as we have left this problem behind us a long time ago and you shouldn't run into it, but that would justify the behaviour you are describing.
Effectively, if I am correct, as soon as you logout you will not be able to log in again as this information is stored in the user's session the first time you login.

Look in vtigerversion.php and vtiger_version database table and make sure they say the same thing.

Let me know how it goes.