SQLITE database locked during transaction - objective-c

Question

I have been trying to figure this out for days now but I cannot figure out what is going on. In my app I want to be able to delete an item, and related items from a tableView. So when the delete button in the TableView is pushed the following method is called.
- (BOOL) deleteDuik:(MOODuik *) duik
{
int diveid = [duik duikId];
NSLog(#"Begin Delete");
sqlite3 *db = [self openDatabase];
sqlite3_stmt * deleteStmt = nil;
BOOL succes = TRUE;
#try{
if (db != NULL) {
sqlite3_exec(db, "BEGIN TRANSACTION", 0, 0, 0);
//NSString *sqlString = [NSString stringWithFormat:#"delete from duik where duikid = %d", diveid];
const char *sql = "delete from duik where duikid = ?";
if(sqlite3_prepare_v2(db, sql, -1, &deleteStmt, NULL) == SQLITE_OK)
{
sqlite3_bind_int(deleteStmt, 1, diveid);
sqlite3_step(deleteStmt);
sqlite3_finalize(deleteStmt);
deleteStmt = nil;
sql = "delete from waarneming where duikid = ?";
if(sqlite3_prepare_v2(db, sql, -1, &deleteStmt, NULL) == SQLITE_OK)
{
sqlite3_bind_int(deleteStmt, 1, diveid);
sqlite3_step(deleteStmt);
sqlite3_finalize(deleteStmt);
}
}
} else
{
NSLog(#"Failed to connect to db");
succes = FALSE;
}
if(succes && ( [duik backendid] == 0 || [self deleteDuikServerSide:[duik backendid]]))
{
NSLog(#"End Delete");
if(sqlite3_exec(db, "COMMIT TRANSACTION", 0, 0, 0) !=SQLITE_OK) NSLog(#"SQL Error: %s",sqlite3_errmsg(db));
} else{
NSLog(#"Failed to delete remote copy");
sqlite3_exec(db, "ROLLBACK TRANSACTION", 0, 0, 0);
succes = false;
}
} #catch (NSException *e) {
NSLog(#"Failed to delete: %#", [e description]);
sqlite3_exec(db, "ROLLBACK TRANSACTION", 0, 0, 0);
} #finally {
#try {
sqlite3_finalize(deleteStmt);
sqlite3_close(db);
}
#catch (NSException *exception) {
//REally nothing to do here
}
sqlite3_close(db);
}
return succes;
}
When I try to run this, it keeps telling me the database is locked, yet I have no idea why it is locked. I have checked to see if other actions require the DB at the same time but I cannot find any. Also, if I add a row from the same tableView, I use the same construction with a transaction and that one DOES work. I have tried everything I could come up with, rewritten this chunk of code at least 10 times but so far no luck.
Is there anyone who can tell me what I am doing wrong here?