[ESPResSo] deleting an interaction

[gil claudio]

How can one delete an interaction. say a LJ
interaction between particles 0 and 1.

Here is my situation.  In a first simulation, I save a
snapshot using checkpoint_set.  This simulation has an
LJ interaction between particle 0 and 1.  I then use
this snapshot as a starting point for another
simulation, this time with no interaction between 0
and 1.  But in the second simulation, the interaction
between 0 and 1 is still calculated.  So how do i
remove this interaction?

Thanks

Gil