Hello, I have just run maxfilter with the options: -autobad on -skip 16 99999 to use the first few data buffers to detect statically bad channels in a continuous data file. Occasionally a channel is reported with a surprisingly large number as in the example output below: > --- Processing raw tag #b = 14/890 (#t = 13.000) --- > Detected 1 flat channels: 1812 > Using direct pseudo-inverse... > Processed raw data buffer with 1000 samples. > > --- Processing raw tag #b = 15/890 (#t = 14.000) --- > Detected 1 flat channels: 1812 > Detected 1 bad channels: 135658288 > Using direct pseudo-inverse... > Processed raw data buffer with 1000 samples. > > --- Processing raw tag #b = 16/890 (#t = 15.000) --- > Detected 1 flat channels: 1812 > Using direct pseudo-inverse... > Processed raw data buffer with 1000 samples. When I tried again with the options: -autobad 16 -skip 16 99999 the "bad channel 135658288" was no longer reported (although the flat one was). So I have two questions: 1) What is this strange channel number? 2) Does the automatic bad channel detection for the first few data buffers differ for the two options, and, if so, how? Many thanks, Danny