Speakers work; Headphones disable all sound

[hackbackwards]

Not sure if this is a sound card issue, but I guess I'll start here and see where it goes.

I've had speakers plugged into my computer for a while now, of varying types. They've all worked fine. About a year ago, I used to use headphones too, so I know that my computer *should* work with both.

I've started using headphones (with a microphone) again, but when I plug them in, I hear nothing. More worrying is that, when plugging my speakers back in (I put the headphones and the speakers into the same jack), I still get no sound. I have to restart my computer to get sound again, and it only works if I haven't plugged in the headphones.

At first I thought it was a problem with the headphones themselves, so I ordered another set (completely different type, but still with a microphone). Same issue. Plugging in the headphones disables all sound, and can only be fixed by a restart.

I've tried plugging them into different jacks (I have two areas on my box that work. I've used them both for speakers and microphones, but never for a headphone/microphone set).

I really don't know what's going on. I've checked connection inside the box, and everything seems okay. I've tried everything in the "Sound problems? Try these things first" thread. No effect.

Sound card: Realtek AC'97 Audio. I use Windows XP Professional, SP3. The computer is custom built.

Any help is appreciated.

[hackbackwards]

Still having a problem.

[hackbackwards]

Yeah, so, I'd really appreciate some help here. Am I in the wrong section?