If the table has more than one index and one of them is a clustering index
then after an offline reorg the table will be fine and sequenced, the
cluster ratio of the clustering index will be a 100% but the other index(es)
may show a cluster ratio less than 80%.
At that point the reorgchk command does not know which index is the
clustering one (it may be one specified in a previous reorg command).  It
will then show that the table needs to be reorg'ed because those other
index(es) may be out of cluster.

Now, if the reorg is INPLACE (meaning online), then the reorg wil do one and
only one of two things, never both:
1) Reclaim space if there is no clustering index defined or index specified
in the reorg command.
       Then a reorgchk afterwards may show that the table need reorg
because some index(es) is out of cluster.
2) Resequence the table according to: An index with a cluster clause or an
index specified.
       A reorgchk afterwards could show need because space could be
reclaimed.

HTH,  Pierre.

It depends on why REORGCHK says that the table needs to be reorganized.
Post the output.

Also, did you update statistics again after REORG?