Sql-server – READ_COMMITTED_SNAPSHOT locking on Non-Clustered Index

I'm in big trouble with one database instance of SQL Server 2008 R2. I have this structure that I've created it to simulate my real problem:

USE [sor]
GO

ALTER DATABASE [sor] SET ALLOW_SNAPSHOT_ISOLATION on;
ALTER DATABASE [sor] SET READ_COMMITTED_SNAPSHOT on;

CREATE TABLE [dbo].[test] 
(
    [name] [nvarchar](50) NOT NULL,
    [id] [int] NOT NULL,

    CONSTRAINT [PK_test] PRIMARY KEY CLUSTERED  ([id] ASC) 
)
GO

CREATE NONCLUSTERED INDEX [IX_test] 
   ON [dbo].[test] ([name] ASC)
GO

ALTER TABLE [dbo].[test] 
  ADD CONSTRAINT [PK_test] PRIMARY KEY CLUSTERED ([id] ASC)
GO

CREATE UNIQUE NONCLUSTERED INDEX [pk_key] 
   ON [dbo].[test] ([id] ASC) 
GO

My problem is that when I execute two or more sessions (transactions) concurrently I'm being locked by some database indexes. To simulate it I start one sqlcmd:

-- sqlcmd 1

begin tran s1
insert into dbo.test (id, name) values(1, 'bob');
go

and start another sqlcmd to be the next concurrent transaction:

-- sqlcmd 2
begin tran s2
insert into dbo.test (id, name) values(2, 'john');
go -- locking here!!!!

When I run the go inside the transaction named s2 I'm being locked.

In order to discover what is going on I run

SELECT * 
FROM sys.dm_exec_requests 
WHERE DB_NAME(database_id) = 'sor' AND blocking_session_id <> 0

Output:

session_id request_id  start_time              status         command          sql_handle                                                      statement_start_offset statement_end_offset plan_handle                                         database_id user_id     connection_id                        blocking_session_id wait_type   wait_time   last_wait_type   wait_resource                              open_transaction_count open_resultset_count transaction_id       context_info   percent_complete estimated_completion_time cpu_time    total_elapsed_time scheduler_id task_address       reads                writes   logical_reads  text_size   date_first quoted_identifier arithabort ansi_null_dflt_on ansi_defaults ansi_warnings ansi_padding ansi_nulls concat_null_yields_null transaction_isolation_level lock_timeout deadlock_priority row_count            prev_error  nest_level  granted_query_memory executing_managed_code group_id    query_hash         query_plan_hash
---------- ----------- ----------------------- -------------- ---------------- --------------------------------------------------------------- ---------------------- -------------------- --------------------------------------------------- ----------- ----------- ------------------------------------ ------------------- ----------- ----------- ---------------- ------------------------------------------ ---------------------- -------------------- -------------------- -------------- ---------------- ------------------------- ----------- ------------------ ------------ ------------------ -------------------- -------- -------------- ----------- ---------- ----------------- ---------- ----------------- ------------- ------------- ------------ ---------- ----------------------- --------------------------- ------------ ----------------- -------------------- ----------- ----------- -------------------- ---------------------- ----------- ------------------ ------------------
74         0           2014-10-01 10:56:54.143 suspended      INSERT           0x0200000098A4BD0B49707895A7295A343EF775E7CF23BCF2              50                     -1                   0x0600170098A4BD0B4001C69D000000000000000000000000  23          1           E24BB9F3-D12A-44EC-944E-FDA206590705 73                  LCK_M_X     1762594     LCK_M_X          KEY: 23:72057594038910976 (020068e8b274)   3                      1                    243137590            0x             0                0                         0           1762596            1            0x000000018281E2C8 0                    0        4              4096        7          0                 0          1                 0             1             1            1          1                       2                           -1           0                 0                    0           0           0                    0                      2           0xF22D2FE93F4C59F0 0x354B4D3AA833139F

and running

SELECT 
   t1.resource_type, t1.resource_database_id, t1.resource_associated_entity_id, 
   t1.request_mode, t1.request_session_id, t2.blocking_session_id, 
   o1.name 'object name', o1.type_desc 'object descr', 
   p1.partition_id 'partition id', p1.rows 'partition/page rows', 
   a1.type_desc 'index descr', a1.container_id 'index/page container_id' 
FROM 
   sys.dm_tran_locks as t1 
INNER JOIN 
   sys.dm_os_waiting_tasks as t2 ON t1.lock_owner_address = t2.resource_address 
LEFT OUTER JOIN 
   sys.objects o1 on o1.object_id = t1.resource_associated_entity_id 
LEFT OUTER JOIN 
   sys.partitions p1 on p1.hobt_id = t1.resource_associated_entity_id 
LEFT OUTER JOIN 
   sys.allocation_units a1 on a1.allocation_unit_id = t1.resource_associated_entity_id

I have the following

resource_type    resource_database_id resource_associated_entity_id request_mode   request_session_id blocking_session_id object name   object descr  partition id  partition/page rows  index descr    index/page container_id
---------------- -------------------- ----------------------------- -------------- ------------------ ------------------- ------------- ------------- ------------- -------------------- -------------- -----------------------
KEY              23                   72057594038910976             X              74                 73                  NULL          NULL          NULL          NULL                 IN_ROW_DATA    72057594038255616

Once I use READ COMMITTED SNAPSHOT I ask you why SQL Server is locking the index? What can I do? I cannot delete the indexes! I need them.