Can not find an approved email

[Anonymous]

I am running two A/B subject line tests using email programs. The second email progarm is a follow up email to everyone who opened the first email (regardless of which subject line they recived). When seting up the second email program, I used the smart list function "opened email" but the approved email from the first test program is not an option in the drop down and the sytem indacates an error if I type in the title. 

Can you not use behavioral information if you are doing an A/B testing?  Why can I not see the approved email from the other test program? 

Thanks

[Anonymous]

The  name of the email in the test is going to bein the format:  Program Name.Test Type, so for example - April Email Program, Subject Line Test.