hi,
i have dir855, bought in Italy and replaced 2 times directly from DLINK by RMA procedure.
After firmware update (actually i'm using 1.22NA), the router was stable with wired connection and 2.4Ghz wireless connection.
The problem is the 5Ghz connection; the signal is poor and when, for example, i try to access into my photo folder (resident on my NAS) and i launch the Microsoft Photo viewer, the router automatically restart and i lose the connection.
WHY?

This is my config.txt
Firmware Version: ver1.22NAb04
Firmware Date: 2010/01/21
ipVersion(Date): 7.6.1b0159 (2010, Jan 18)
ipOS SDK Version: 7.6.3 P (1134)
WAN MAC:
LAN MAC:
WLAN MAC 0:
WLAN MAC 1:
Wireless Region 0: 0x0E
Wireless Region 1: 0x0E
Radio 0: 2.4GHz Band
SSID: xxxxxxx
Radio 1: 5GHz Band
SSID: yyyyyyyyy
SubVendorDeviceID 0: 0x2081
SubVendorDeviceID 1: 0x2082
Wireless Domain: 0x37
Firmware Notify URL: http://wrpd.dlink.com.tw/router/firmware/query.asp?model=DIR-855_AX_NA
Firmware Global URL: http://wrpd.dlink.com.tw/router/firmware/DIR-855/Ax/NA/DIR855A2_FW121NAB04.bin
Checksum: 0x042C55E4
Use non DFS channel only: Enabled
This version is Release version
USB_IP/K=Disable
USB_IP/S=Enable Version 1.1.1
WLAN 0 Channel List: 1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13
WLAN 1 Channel List: 36, 40, 44, 48
HW Ver: A2
tks
Freeman