Windows 7 - Xonar ds sound volume fading in and out issue

I just bough a xonar ds card to replace the onboard realtek 892. I had some minor issues with the cd that came with the soundcard, as it only had Vista drivers. Didn't realize at first and let it install. Sound did not work at all. I then uninstalled both realtek and vista drivers in safe mode and downloaded Windows 7 drivers from Asus's website. I've got sound and gaming sound is excellent(especially in wolfenstein) but when i play music, no matter what i use, be it j river media center through ASIO or WASAPI, or if i use win media player, when the song starts, the volume fades in and out. For example when listening Nightwish - storytime at the begining the instrumental is made of high notes, sounds clear, but when the guitar and bass kick in, the volume fades down all together, and then the high come back at the normal volume. I'm not sure if i expressed it right, but i get this issue with most of the songs i listen. Some are .mp3 others .flac or .wma lossless. The issue is there regardless if i use headphones or speakers. Could it be due to the sound card, or would a win reinstall solve the issue? Thank you.

Running: AMD Athlon II X3, XONAR DS 7.1, Win 7 x64.

The XONAR DS Audio Center is set to Audio Channel: 2 channels
Sample Rate: 192Khz
Analog Out: 5.1

Note: issue appears with both 192Khz and 44.1 Khz

ISSUE RESOLVED

Stupid ME. Never thought to actually check the mixer of XONAR DS AUDIO CENTER. It has a master volume and also individual volume for each channel. On default, each channel is set to the standard 100% (showing as 78% in the audio center). If you push those to max the card will amplify each channel above the 100% limit, causing the issue i described. All works excellent on 192Khz 24bit 5.1 output with WASAPI and ASIO with the mixer on default. Thanks and sorry for starting a useless thread. Oh, for future note to anyone who sees the thread. The XONAR DS does not have an EMI shield. I initially installed it on the PCI next to the graphics card. The cooler of the card was 5mm away from the sound card. I later switched the sound card pci with that of the tv tuner(the latter being farther away from the graphics). Apparently EMI is 0 or unnoticeable now. The graphics card in so close proximity was causing a bit of EMI(better said, the running engine of the cooler). As an advice, try to install your soundcard as far away from the graphics card as possible.