That is generally the case, unless it was previously sold to a collection agency and they charged it off as well...
I have one account listed as such: 30, 60, 90, 120, C/O, C/O, C/O. I filed for bankruptcy and the charge offs are listed on the month before, the month of, and the month after I filed. This has got to be hurting my score since they should only be able to report it once.
They are only reporting it once. If it had been charged off after you filed BK it would have been unrated and reported as IIB. Wrong.
They aren't re-reporting that it is COed... They are updating that as of the date that they are reporting the debt is still currently COed... They can update the tradeline monthly if they choose to do so, they are only reporting that the current status is COed, and the CRA is displaying that as the history of the tradelines reporting.