Ok guys, heres a weird one for you.
I have written myself a function that I use to commit all transactions:

***************************************************
int commit_transaction(isc_tr_handle* tr){
ISC_STATUS status_vector[20];

if(isc_commit_transaction(status_vector, tr)){
//Error Routine
return -1;
}
return 0;
}
*****************************************************

It appears to work fine everwhere but the instance in the following
code. The commit call gets the following error.
"invalid transaction handle <expecting explicit transaction start>"

***************************************************
// variable delarations goes here

if(isc_dsql_execute_immediate(status_vector,
&db,
&tr,
0,
SQL,
1,
NULL)){

/*
Error routine
*/
}

commit_transaction(&tr); // <---- This errors!!!

detach_database(&db);
return 0;
***************************************************************

If I chane the commit_transaction call to the API call

isc_commit_transaction(status_vector, &tr);

it works............

Any ideas? Could this be na issue with the C compiler?