Could not bfget in Informix IDS 7.31

Hi. I have a problem with some tables in IDS 7.31 whose data seem to be corrupted. When I do a Check on the table mark_translation it appears: TBLspace data check for copyprod:euroadm.mark_translation Table fragment in DBspace pem_data3 Table fragment in DBspace pem_data2 Table fragment in DBspace pem_data1 Table fragment in DBspace pem_data4 Could not bfget pagenum 3c50, iserrno 0 It involves that I cannot do a nested query: select * from mark_translation where ... in (..) As well I have some chunks DOWN so I have the following questions: 1) Is it only a register which is DOWN or it an entire PAGE? Is it possible to know which are? By 3c50 I understand that the page/register 15440 (3c50 in Decimal) is wrong ? 2) Is it possible to drop this registers corrupted? How to do it? 3) How has become this registers corrupted? Is it possible to control that it does not happen any more? 4) The corrupted chunk provokes that the chunk where it is placed becomes DOWN? or since the chunk is DOWN then the page where it is stored becomes down too? 5) Which alternatives I have to solve the problem? Thank you all. Alan