Maybe you can change only season and map rules, not map index?
RegisterMap( 0, 0, 0, 7168, 4096, 4, "Felucca", MapRules.FeluccaRules );
RegisterMap( 1, 1, 1, 7168, 4096, 4, "Trammel", MapRules.FeluccaRules );
if you want use same map index, send your crashlog...