I haven't ever left it in the carboy for an extended amount of time, I usually let it age in the bottles as I hate tying the carboy up as well.
Is the rotten part a taste or a mild smell?
If its a sulphery/rotten smell that is normal, and it should dissipate. I am not sure if I would bottle it yet if its a smell although I haven't had that issue yet so someone else could help you better.
From the threads I have read if you are kegging it, carbing it up and releasing the pressure a few times is supposed to be able to 'scrub' it out of there.
Since you are a month out I would probably at least rack it off the leese if you haven't already, I have heard that can lead to off flavors.