To stop the repeated login issue please try the following:

To fix the issue please try the following:
1- Restart the program and enter your email and password combination into the login screen and select "Use Existing Account" as you have been doing

2- When the account information screen appears do not select "Continue" but leave that window open and open Windows Explorer to (For XP: C:\Documents and Settings\All Users\ApplicationData\FlightPrep) (For Vista or Windows 7 C:\ProgramData\FlightPrep)

3- In that folder you will see a file named key.license. Please r-click on the file and select properties

4-Once you see the properties window locate the check box for "Read Only" and select it then select apply and OK

5-Close out of the folder and select continue on the start up for your software

6-To verify that the issue is resolved close and restart the application

Please send email to support@flightprep.com with questions.