A limitation of AFNI is that you can't transform functional datasets from AC-PC to Talairach properly. This is more complex than you might think -- I tried to put it in the code once, but gave up.
The clumsy workaround is to transform the datasets (lesion tracings) from AC-PC to Original, then on to Talairach. The AC-PC to Original transformation can be done with 3dfractionize, using the -warp option. Then (if you have the anatomical +orig dataset) AFNI will make a "follower" dataset from the func+orig dataset in the +tlrc view. I recommend that the func+orig dataset get a different prefix name than the lesion +acpc dataset, so that no possible file clobbering can occur.
Hope this helps -- bob cox
