Problem Windows 8 logon script not working from windows server 2008 R2

hi there , this is third post regard this problem, here is my problem goes .....

Is a very simple logon script for mapping drive purpose .... PLS take note Domain users can access and run this script for domain users using windows XP / WINDOWS VISTA / WINDOSWS 7 and only  users " WINDOWS 8.1 " Does NOT run at all . the script I put on logon script in Windows server 2008R2 group policy ... 

@jrv :- http://social.technet.microsoft.com/profile/jrv/?ws=usercard-mini , insist said is my group policy setup problem so I post here agn...

Manually run the script on WINDOWS 8.1 is 100 % perfect so it is definitely not my logon script issue , PLS any guidance pls share for me ok ?? thanks

Below is my script syntax ;-

@echo off
REM Login.bat Version 1.0
REM Exit if user has logged on to the Server
IF %COMPUTERNAME%.==SL2011. GOTO END
REM Delete pre-existing drive mappings
REM
REM Map M: to SL2011 on sl2011
NET USE M: /DELETE >nul
NET USE M: \\SL2011\sl2011 /YES >nul
REM
REM Map Y: to AccScan on rss2
NET USE Y: /DELETE >nul
NET USE Y: \\rss2\Public\AccScan /YES >nul
REM