Hardfault in freeRTOS MTU Exchange (MTU>=200)

I'm using the ble_app_grs_freertos example.  I'm trying to maximize its thru-put potential for Central devices which can support the high data rates.  For this I've used the follow GAP Setup parameters.

NRF_SDH_BLE_GAP_DATA_LENGTH 251

NRF_SDH_BLE_GAP_EVENT_LENGTH 6

NRF_SDH_BLE_GATT_MAX_MTU_SIZE 247

with a stack configuration of: 

ble_cfg.conn_cfg.params.gatts_conn_cfg.hvn_tx_queue_size = 4;
err_code = sd_ble_cfg_set(BLE_CONN_CFG_GATTS, &ble_cfg, ram_start);

Everything initializes fine and starts advertising.  However when I connect to an iOS nRF Connect App everything crashes.  I hit a hardfault @ 0x0002C03A which lies in the           vTaskSwitchContext call inside the freeRTOS source code.  With the nrf_log on debug I see the following messages from start-up to connection.

<debug> nrf_sdh: State request: 0x00000000
<debug> nrf_sdh: Notify observer 0x00037A9C => ready
<debug> nrf_sdh: State change: 0x00000000
<debug> nrf_sdh: State change: 0x00000001
<debug> nrf_sdh_ble: RAM starts at 0x20002D88
<debug> nrf_sdh_freertos: Creating a SoftDevice task.
<debug> nrf_sdh_freer<debug> nrf_sdh_ble: BLE event: 0x10.
<debug> nrf_ble_gatt: Requesting to update ATT MTU to 247 bytes on connection 0x0.
<debug> nrf_ble_gatt: Updating data length to 251 on connection 0x0.
<info> app: Connected
<debug> nrf_sdh_ble: BLE event: 0x24.
<debug> nrf_ble_gatt: Data length updated to 27 on connection 0x0.
<debug> nrf_ble_gatt: max_rx_octets: 27
<debug> nrf_ble_gatt: max_tx_octets: 27
<debug> nrf_ble_gatt: max_rx_time: 328
<debug> nrf_ble_gatt: max_tx_time: 328
<debug> app: ATT MTU exchange completed. central 0xF7 peripheral 0xF7
<debug> nrf_sdh_ble: BLE event: 0x3A.
<debug> nrf_ble_gatt: ATT MTU updated to 185 bytes on connection 0x0 (response).
<debug> app: ATT MTU exchange completed. central 0xF7 peripheral 0xF7
<error> hardfault: HARD FAULT at 0x0002C03A
<error> hardfault: R0: 0x00000040 R1: 0x20005EDC R2: 0x20005E04 R3: 0x002B5E18
<error> hardfault: R12: 0xA5A5A5A5 LR: 0x0002A791 PSR: 0x8100020E
<error> hardfault: Cause: Data bus error (PC value stacked for the exception return points to the instruction that caused the fault).
<error> hardfault: Bus Fault Address: 0x002B5E24

As a note I did update the linker file to the following settings: RAM (rwx) :  ORIGIN = 0x20002d88, LENGTH = 0xC8E8

The odd thing is if I reduce the MTU size to 198 everything works fine.  Any ideas?  This whole data-thruput maximization seem to have alot of moving parts, making it.  

EDIT:  This was addressed in the latest SDK update.  Thanks