Informix Error -346; ISAM error -121

I am using Informix-SQL ver 4.1. When I run the following command: update maintenance set labor = 0 where completed is null and shop > 7203 I get the following errors: 346: Could not update a row in the table 121: ISAM error: cannot write log record. The database was created in a previous version of Informix and converted using sqlconv. I unloaded the table data from the old version, ftp'd the file to the machine with the 4.1 version, and used the load statement in the Query-Language menu. I am not using transaction logging. I can't figure out which log the message is referring to. Any help/suggestions will be very appreciated. jkharris@utk.edu