Binding a non-repeating control to a repeating field or group is not supported by InfoPath Forms Services. To fix this problem, remove the control or replace it with a repeating control, such as repeating section or table."
I automatically assumed that this would be the same as other "errors" and would prevent the publication and activation of this form. This is not the case. In fact, the Design Checker should really should show as a warning, as you can safely ignore the "error" and publish anyway.