MPC (both MPC and MPC-HC) - directshow audio device choice

[_saiko]

i have 2 soundcards on my system
realtek onbard and realtek HDA HDMI (graphix card HDMI output)

in MPC in the dropdown menu for directshow audio device output i have:
Directsound: realtek onbard
Directsound: realtek HDMI
+
default direct sound device

when i select "Directsound: realtek HDMI" i get the output from my onboard card INSTEAD of HDMI audio device
and when i select "Directsound: realtek onboard" i get an error (as if there are no codecs...) and no output from HDMI audio

my system default device is the HDMI audio so when i select Default directsound device i manage to get the HDMI audio to work

so my guess is something's wrong with the identifiers... ?
anyone had a similar issue or is there a way to solve this annoyance?

many thanks