Character to Integer Conversions

Hi, I have a function that is passed 2 parameters and stops at line <here> somtimes (only 3 times in 6 months) but most of the time it works fine DEFINE passed1 LIKE some_table.column1 ->> CHAR(12) passed2 LIKE other_table.column2 ->> SERIAL LET passed1 = "11" LET passed2 = 59 CALL some_function(passed1,passed2) FUNCTION some_function(key_arg1,key_arg2) DEFINE key_arg1 LIKE some_table.column1, key_arg2 CHAR(3), loc_num INTEGER WHENEVER ERROR CONTINUE LET loc_num = key_arg2 #-stoped at program line <here> IF STATUS != 0 THEN LET loc_num=0 END IF .............. FORMS error -1207 converted value does not fit into allotted space A noncharacter value, after conversion to a character string, is too long to fit in the buffer that was provided. If the conversion was automatic, change the program to provide a larger host variable to receive the string. If this was an explicit call to conversion function pass a larger buffer. .............. i've tried re-creating the error using the same data "SAMPLE" and 59 but can't get it to crash,have also tried passing NULL and big numbers to key_arg2 assigning CHARs to INTEGERs probably is not a great idea but why does it fail sometimes ? any ideas appreciated ALTOS UNIX INFORMIX-SE 4.00UE2 altos series 2000 altos sys V 5.3ET2o INFORMIX-4GL 4.00UE1 altos series 2000 altos sys V 5.3ET2o