In the universal interface of tauola there is a check to eliminate search 
for the tau-leptons in so called,  "history" part of the record.
This is performed with the help of subroutine PHYFIX.

There are 3 versions of this routine here. 
 phyfix.general  in case when there is no need no possibility to check history
 phyfix.lujets   in case when lujets common block is used by JETSET or PYTHIA.
                 (variables single precision dimensions 4000)
 phyfix.pyjets   in case when pyjets common block is used by PYTHIA.
                 (variables double precision dimensions 4000)

The actually used is phyfix.h. You must copy the one you need to this file.
In some cases you will need to re-edit it by hand. Eg. if in your version of 
Pythia dimension is 10000.

As default we give a version  phyfix.general which does not calculate
history position at all. It can be used with any generator, but you may 
encounter difficulties if the history part of the event was looked.

We recommend to take the appropriate version. In case of host MC
differant than JETSET/PYTHIA we recommend to provide routine 
able to define the end of the history part of HEPEVT record (if existing).

