Time-frequency analysis potential discrepency

[arnodelorme]

"The individual subject plots
look fine to me when I go to "channel time frequency", i think the
data are ok (see attached figure of the FC1 channel of one subject).
However when I plot the mean ersp plots for the three groups i see
strange results (see attached image). Of note, the time window I see
is not the one I specified in the parameters button. Then, when I try
to plot the single-subject plots (same FC1 channel) in the study
interface, as you suggested, I get an error (see screenshot).
I hope this might help to understand my problem"