Possible Duplicate:
Dismiss flags on the same posts with different validities
On Drupal Answers, I got the following flags for a post.
As for what happens now, when the question is closed, both the flags would be marked as helpful, while the first one is not helpful. As moderator, I cannot handle the first flag, without to handle the other one. In this case, I would decline the first, and let the users handle the second flag.
I would be in the same situation when, for example, a user flags a question because it has been created with an unregistered account the user created by mistake. I can merge the accounts, but I cannot handle that flag separately from another flag existing for the same post, with the result that another moderator would step in, and check if the accounts effectively need to be merged, when I have already taken care of this.
In both the cases, it would be (IMO) preferable to handle the custom flag separately from the others.