I am also the "Not-so-proud" owner of a Phoebus soundcard.
My problem description - Battlefield 3 will slow down to a crawl and freeze while giving out a steady "feedback" sound which shifts tones for every frame it advances. The freezes seem to appear after ~10 min of gameplay. The game will then quit to desktop.
Motherboard: MSI Eclipse (Latest Bios)
CPU: Intel i7 920 (Latest Chipset, not OC'd)
VGA: Sapphire 6970 Toxic Edition (Latest AMD Catalyst, not OC'd)
RAM: 12GB DDR3 (Also not OC'd)
Windows 7 Enterprise x64
Latest DirectX Drivers
Phoebus Driver version: 22.214.171.124
Firmware Version: 1014
CPL Version: 126.96.36.199
Since BF3 is the only game I play right now I cannot confirm problems with other games.
But I can successfully pinpoint the issues to the Phoebus card and/or its drivers.
I have tried what I believe to be the most complex variation of combinations of settings in the Phoebus Control pannel, without any kind of improvement or worsening of the issue.
My previous card(s) - Creative X-Fi Titanium, Onboard (Realtek) and a Plantronics USB headset (just for testing, the Phoebus has only a Sennheiser PC360 Attached to it).
All other cards have been (of course) either physically removed or deactivated while the Phoebus is installed.
NONE of those cards ever caused any issues. Not to mention my computer has never, not once, caused neither a crash, freeze, bluescreen or whatsoever under an circumstances.
Problems started after installing the phoebus card and cease as soon as the card is replaced and drivers removed.
I have also managed to reproduce the problem by installing the card on my GF's PC (Similar specs, but completely different hardware vendors).
After reading most of the posts in this thread, it is more than evident that this is not only a very common issue but it also seems to be a universal problem and not just an isolated issue.
Needless to say, I am extremely disappointed with ASUS - not only for delivering sub-par quality for a USD 200+ soundcard (HEY! Other people buy almost a whole PC for that money!) but for the lack of support it has received so far. ASUS claims to be the biggest computer components manufacturer in the world, yet they seem to invest more time and money covering up their mishaps than trying to fix them.
I just hope this is not a general hardware design issue...
PS: The other issue I am having with this card is rather hard to explain... When watching a movie/video it seems as if the volume raises the longer you hear speech... as if in... hmm... a curve starting at a very low barely audible volume, and after the first 0,5sec or so that a character starts speaking it will peak in volume and just before he ends his sentence the volume will drop down to almost zero again.
to whoever cares... thank you.