On Windows 7, if I set the Playback sample rate to 48kHz, and then use the Tone Generator to play back a sine wave, I can hear an artifact which sounds like aliasing. If I set the playback rate to 44.1kHz, the tone sounds very pure. I am testing with low frequencies (say, 50Hz).
I first noticed this problem in YouTube, and I have crossposted in a few places, including the Windows Pro Audio Developer forum:
http://social.msdn.microsoft.com/Forums/en/windowspro-audiodevelopment/thread/725546ce-57bf-40d0-b7aa-47e51de9c3ae
System:
Toshiba NB300 netbook
Windows 7 Starter Edition
Are you using the old "WaveOut" API, by any chance?
Regards,
Greg.