dolby digital 5.1 not working. I cannot figure out why

[syntholik]

Hi all,

I have an audiophile 2496 card using the spdif output to my AVR-520 receiver. I am trying to play ac3 dolby digital 5.1 divx's but my receiver is only seeing the bitstream as pcm 2 channel digital audio (it does play but not 5.1) I installed the audiofilters.zip from doom9 but that only allowed me to actually hear the sound (but still 2 channel) I set the audio format to 6 channel but that doesnt seem to change anything. One of the audio filters is showing 2 channel DOLBY SURROUND and cannot change it. the 5.1 is greyed out. (I cant remember which filter I was looking at now) another one of them did show the audio as ac3/48khz/5.1 so the content is okay (I tried it with different divx's so it isnt the divx itself) and another filter is showing it's using directsound.. is this normal? could directsound be corrupting the bitstream or downmixing it somehow?

I am really at a loss.. and would appreciate any assistance that anyone could provide!

Thanks