When I run concheck -ci Informix send me an error in an index, with
following message:

Error: Bad node links. 5d'1 prev 5c != 5b

What's wrong?

I'm working with Informix IDS 7.31 (TC2 and TC5), on Windows NT 4.0
Server SP 6a

Is a bug of the version? because, I exported this database and
imported it into INFORMIX IDS 2000 9.21 and the problem dissappeard!!!