James,

The first issue you are having is only applicable when you set concatR=1.
When you set concatR=0, this won't happen. I'm working on changing the
concatenation to not combine the tasks by accident as it did in your case.
It's matter of setting the correct regular expressions in my matlab code
for spm_estimate_ppi.

The second issue occurs whenever P.contrast is not defined OR when it does
not 0. I'll work on updating the manual and also updating the error dialog
to be more informative if the error is due to the first level model having
not been estimated.

-Donald