not recording audio RT with fixed sound stim

We are delivering an n-back using a wireless logitech headset with microphone.

We are having difficulty in recording the audio reaction time when also recording to a wave file. We want to have a fixed time between the sound stimulus of each trial, record the trial response to a wave file and record the audio reaction time.

We have a letter stimulus to the computer screen (time set to 0) followed by the sound letter stimulus with time set to: rt:aud,rec,2000 -similar to the stroopfixed sample.

In the log file from the trial, all our RTs are 2000. If we remove the record command and set time (rt:aud), the program does record the accurate response so the microphone is at the right setting. If we remove the record response but try to keep the fixed time stimulus (rt:aud,2000), the program still waits for a response before moving on to the next trial, but does measure the RT appropriately.

Any thoughts on what I am doing wrong?
Thanks!

Not sure if it was a combination of my hardware: logitech wireless headset (G930), or computer (IBM leveno thinkpad, windows xp service pack 3) BUT goint back to version 2008 works fine - fixed sound stimulus, auditory RT and recording audio response to a wave file.