Vista - Please help! Very strange problem..!

So I've tried pretty much everything lately, and this is my last resort before i RMA the damn board

A little background info first; this is the 5th system I've built.

Intel dx58so mobo
Diamond HD4870 1 gig
Intel i7 920 2.66 ghz
3 gig (3x1) G.Skill 1333 mhz memory
Antec PSU 650W Blue Neo Power
Seagate 250 7200 RPM 32 MB Cache
Samsung 22x DVD-RW
Antec 1200 Case

Currently running Vista Home Premium 64bit

So I put it together 4 days ago, and everything was working just perfectly. Then, out of courtesey for my GF who was watching TV, i decided to use my SONY MDR V-700 headphones when gaming TF2. Earlier, i had been using a Bose speaker setup with a Subwoofer and RL speakers. Those were plugged into the onboard audio in the back, that comes with the intel dx58so mobo. It was working fine.

So i plug in the headphones in the front panel on the Antec 1200 case, and then sound dissappears. I hear some static, but don't think much about about. So i go the volumebutton in the systray, and find out that the only playback device available now is HDMI High Def Audio (?!). Previously, there was 4 other options. Now there is no sound in any of the regular jacks in the back, nor the front panel.

I've tried completely formatting and reinstalling windows, used latest patches. Manually removed drives and uninstalled the sound device, nothing works. I even tried installing the latest Realtek drivers from the realtek site alongside the newest mobo drivers from Intel. It still can't find any other playback device than HMDI High Def Audio.

Moreover, there used to be another sound icon in the systray, a bronze Realtek controlpanel icon, that is gone now. Last thing I saw from it was that a popup said i had plugged in and out a headphone jack (the frontpanel on the Antec 1200 case). Even when i reinstall it, it still doesnt appear in the systray, and I can't even start it manually from the folder.

So, if ANYONE knows anything about this problem, please help !! Intel customer support was useless..

- Stein