If you logged off of Yahoo!, then relogged in with a different ACCOUNT (different ID, different password) then you may, indeed, recommend twice.
However, PROFILES are simply 'identities' for the same login. If you have multiple ones, the drop-down dialog box that says 'Select an identity' appears whenever you post a message. Here, in my case, is where I select from one of my three profiles previously identified (CP, AL, CK).
Unless you logoff/logon again, you can only recommend a post once.
As I have said many times in various contexts, I have only one Yahoo! account that I have had since 1998. I have three profiles.