try changing the audio buffer size when set to low or high this causes the robotic sound, (for me only 2048 works good)
and be sure to have the correct output selected.
you can try asio directx divers for onboard audio, it handles the buffer size different.
you can try to separate the video and audio, drag your clip twice into the composition, on one delete the video track, on the other delete the audio.
are you sure, the HDD can read the file fast enough?
you can check the Windows audio settings too, like you say output was switched to hdmi.
sample rate should be the same as in resolume, and the same as your files.
disable sound card exclusive mode.
i use a Dell vostro and i had difficulties with audio drivers from dell, sometimes the audio quality on low audio levels changed , like it was going to mono and 8khz, now using the stock win7 drivers, and it runs more stable.
you can try to manually delete resolume config file, to be sure to get back to installation defaults.