INFORMIX database - Problem with INSERT

Hi, Overview : ------------- We have an Informix database (SE) installed for storing test cases. But in the recent times we are experiencing a strange behaviour while inserting some entries into the database.Typically the database seems to be working fine and we are able to perform all the queries on the database. Problem : ------------ We started experiencing problems while INSERTING entries into the database from past few days. Usually in the morning the database is working fine and we are able to even perform the INSERT operation succesfully. But after few hours of usage, the problems start and when we try to INSERT any entry we get different errors. I have listed down some of the errors below : ----------------------------------------------------- 311: Cannot open system catalog (syscoldepend). 311: Cannot open system catalog (sysusers). 45: Operation not supported on socket Surprisingly, some times very rarely the INSERT and UPDATE operations will also work. But once you start using the database more, again we get errors like : -------------------------------------------------------------------------------- - Prepare statement failed or was not executed. - Could not open database table (node.proj). [ proj is the name of a table in our database ] - Error reading constraint index on table (node.plat). [ plat is the name of a table in our database ] [ After each attempt, the error sometimes changes to a different table like customer, sales etc. ] Can any one of you please help me in resolving this issue. Any suggestions are most welcome. Thanks in advance, Anu