-1215 errors when using the ESQL/C "EXEC SQL SET DESCRIPTOR" comm

Hello, I am having problems with getting a -1215 Informix error when executing the ESQL/C "EXEC SQL SET DESCRIPTOR" command. The program that uses this command first uses the "EXEC SQL PREPARE" command to prepare the SQL statement then uses the "EXEC SQL SET DESCRIPTOR" command to insert the data into the SQL. This program works for about 5 days of continuous use. It then gets the above error. I have checked the data that is being inputed and it is the correct type. The -1215 error states that the Value was too large to fit an INTEGER. The error happens on integer, char and float fields. The program is running on a NCR / AT&T Unix platform, running Informix versions: INFORMIX-SE Version 5.10.UC1, INFORMIX-4GL Run Time Facility Version 4.20.UC1 and INFORMIX EMBEDDED SQL Run Time Facility Version 5.10.UC1. If anyone has seen a similar problem or has any other trouble-shooting information for informix, please let me know..... Thanks, Mark Secrest