Clang sqlite3 float error - c

Question

Any ideas on how to track down this error would be appreciated.
I have some c code that runs in two or more processes. The first process listens in on a message queue and saves the resulting struct to a database. The remaining processes query one or more serial devices and pass this information through the message queue to the first process to be stored in the database.
It all works great except the following. One of the structs I am using contains a float. This struct gets sent through the queue and decoded correctly however when binding the value using sqlite3_bind_double() the resulting value in the database is 0. Placing a printf() statement around the sqlite3_bind_double() statement causes the code to work and place the correct value in the database.
But even more interesting is if I remove the printf() statement and compile the program with gcc the code works.
Any help would be great. Thanks in advance.
Code:
int
add_inverter_stat(sqlite3 *db_conn, struct inverter_stat const *istat
,int *sqlite3_err)
{
sqlite3_stmt *stmt = NULL;
*sqlite3_err = sqlite3_prepare_v2(db_conn, SQL_INSERT_INVERTER_STAT, -1
,&stmt, NULL);
*sqlite3_err = sqlite3_bind_int(stmt, 1, istat->stat_id);
*sqlite3_err = sqlite3_bind_text(stmt, 2, istat->serial_no, -1, NULL);
*sqlite3_err = sqlite3_bind_int64(stmt, 3, istat->time_taken);
*sqlite3_err = sqlite3_bind_double(stmt, 4, (double)istat->value);
*sqlite3_err = sqlite3_step(stmt);
sqlite3_finalize(stmt);
return 1;
}

Answer 1

That's the sort of thing I would expect from something trying to read a four-byte float as an eight-byte double, with the other four bytes being ... well, whatever. This really shouldn't work, but if you put an explicit cast (double)flt_var as the third parameter, does that help?