[Eeglablist] problem interpolating channels

[Jason Satel]

Hi All,

I am having some issues interpolating channels using EEGLAB. This is  
my first full ERP experiment so any help would be appreciated.

The problem is that when I run the interpolate function, it says, for  
example,  "Interpolating 4 channels...", but then does not actually  
update nbchan or the number of channels in EEG.data (although  
sometimes it does work for some subjects, but I can't find a  
difference between the datasets that work/don't work - although the  
same datasets consistently work/don't work even if I restart the whole  
analysis). It seems like the channel locations are getting 'lost' and  
then cannot be replaced once channels are deleted.

My basic analysis procedure:

1) import bdf file, & high/lowpass filters,
2) get channel locations ( EEG =  
pop_chanedit(EEG,'lookup','/Applications/MATLAB_R2008a/toolbox/eeglab9_0_3_4b/plugins/dipfit2.2/standard_BESA/standard-10-5-cap385.elp');  
),
3) remove bad channels using visual inspection
    (e.g., EEG = pop_select(EEG,'nochannel',{'P1' 'EXG7' 'EXG8'}); )
4) average, baseline correction & rereference to average
5) remove bad trials (+/- 75uV, but not eye movements)
6) run ICA and remove bad components (eye movement related)
7) interpolate missing electrodes
    ( EEG = pop_interp(EEG, ALLEEG.chanlocs, 'spherical'); )
8) rereference, re-baseline correct, remove additional bad trials
9) plotting, stats..

Then, when I try to reference to the average on the datasets that  
didn't interpolate properly, I get the following error:
"eeg_checkset warning: number of channels different in data and  
channel file/struct: channel file/struct removed
Re-referencing ICA matrix
Warning: Wrong channel indices, removing ICA decomposition
> In pop_reref at 269
??? Undefined function or variable 'dsafdsf'.
Error in ==> pop_reref at 270
             dsafdsf "

Cheers,
Jason Satel