Precompilers, OCI & OCCI :: Variable Declarations In DECLARE SECTION?

I am getting some odd results from a Database Insert Function. The function receives an Array of elements. The elements are a defined structure (containing around 21 data items). I need to insert these records into an Oracle table.For each element of the Array the function reads the structure into a local c structure of the same type.

I then go through this local structure and get a copy of the data into local variables declared in the EXEC SQL BEGIN DECLARE SECTION of the function. I then use the local vars to do the insert, using null INDICATOR variable to handle those variables that could be empty. The local variables look like this....

EXEC SQL BEGIN DECLARE SECTION;
int dbServiceTypeId;
int dbRecordType;
char dbRbmCustRef[MAX_CUST_REF_LEN];
int dbServiceSeq;

[code]...

BUT.. when I uncomment the dbCOS variable (even though I don't populate it or try to include it in the insert) I get the following in the table (The RATE value goes missing completely and the multiplier is wrong)...

ID SERVICE CODE R/T RATE MULTI
41325-SCODE-1084 1 542139762
11326-SCODE-1086 1 542139762
11326-SCODE-1086 2 542139762
21327-SCODE-1087 1 542139762
21327-SCODE-1087 2 542139762
21327-SCODE-1087 3 542139762
21327-SCODE-1087 3 542139762

However, a printf statement just before the insert based that returns the variables shows the following...

Service Type ID: '4'
Record Type ID: '1'
Service Cust Ref: '1325-SCODE-1084'
Service Unit Rate: '1200.00'

Indeed, for this record the Multiplier doesn't even get populated. The other odd thing is if I recomment the dbCOS but remove the dbOraDateFmt variable definitions, it corrupts the data again, though different fields. I can't understand why individual local variables are behaving this way. Is this a problem with the way variables are declared in this section?