Mysterious bug: sound is very quiet

[batonsu]

This is very strange. First, I took the standard wiki example from here. There were no errors, but the output was abnormally quiet (the default output on my laptop is "Realtek High Definition Audio"). Then, I plugged an HDMI cable into my laptop to stream the output to my TV. In this case the volume is fine (I double checked all the audio devices' settings in Windows). More on that, if I switch back to "Realtek" but use 64-bit JVM to launch the application from Eclipse, everything is fine again. Summing up, this bug only occures when all of these requirements take place:

1. When using the default "Realtek High Definition Audio" output device (not the HDMI output).
2. When using 32-bit JVM (not the 64-bit JVM).
3. When running from Eclipse (when I exported the app into runnable jar and executed it with the 32-bit JVM, everything went good again)

Maybe anyone could suggest something on how to find the cause? Although it works as expected in most cases, I'm kinda scared of unpredictable behavior, who knows how it is gonna work on a user's machine?

My configuration: amd64 laptop, Windows 7 64-bit