Got at ASUS Xonar DX PCIe sound card for my HTPC

. Connect it to my old Harman Kardon AVR 3550 via Digital Optical. Plays pretty fine

but the sound card and Receiver both are capable of 192Khz 24 bit however the display on the Receiver still says "DVD/96K" for any 96K or 192K FLAC songs played through it

. Also tried DD 2.0 and 5.1 content, fiddled with all the settings of the card, the player(media player classic, WMP 11, vlc) still the same issue
Can some one pls help me through this, as to how to get 192Khz sampling through my HTPC-Receiver combination?