audible artifacts in output of Tact 2.2X

I just purchased a used Tact 2.2 X and overall I am pleased with it's performance. However, I have now noticed with the correction enabled, some tracks that I play at high volumes will exhibit a low frequency tone burst at around a few hundred Hz, very short (<200 msec). Specifically the "LA LA LA " reframe in the Cowboy Junkie's version of "Sweet Jane" on the Trinity Session CD which has some pretty loud low frequency stuff in it. This noise is coming out of the front (main) speakers in the 2.2 mode not the subs. Crossover freq is 100 Hz. I have traced the noise down to the Tact unit by switching speakers and amp channels. I hear this noise with all corrections curves and with digital or analog input. I do not hear this noise in the bypass mode.
I talked to Tact and asked them if the correction filters could have been corrupted during upload and they said that was practically impossible. I still think this might explain my problem. I intend to reload my curves and try again.
My curves are pretty flat +/- 3 db at most, nothing radical.
Has anyone else using the Tact come across anything like this.
Thanks in advance or any response.

Spec1A