The Arabs never made it even close to the Kingdom of Kashmir let alone the Kashmir Valley. Also Mahmud of Ghazni (Turk) was twice defeated by Hindu Kashmir. Kashmir has a solid history in the Rajataringini. Even at the height of their power the Arabs could only make it to Sind and Multan on the Indian subconitent. They were then defeated soundly by Lalitaditya and Bappa Rawal.  For further reading see- http://www.scribd.com/doc/416177/The-ChachnamaAn-Ancient-History-of-Sind
http://www.ummah.net/history/scholars/BIRUNI.html

If people want to change the history of this region as this does not suit therm, they surely can not.