Schedule B line 7A

When Turbo Tax is checking for errors, I get a message that line 7A must be checked yes or no.  I click on no.  Run smart check again and it says line 7A must be blank.  It won't allow me to continue because of this.  When I check the "NO" block it errors out saying it must be blank.  If I try to leave it blank, it says must be yes or no.  What's going on?  I need to check the no block, but it errors out with smart check.