Forcing leptonic tau decay with TAUOLA /pythia

I saw some other questions with similar problems but none of the solutions in those seemed to help me.

I generated a p p > ta+ ta- process with MG and subsequently wanted to shower it in Pythia. Right now I am using the sm-full model, but I have also tried this with sm and with heft (I actually want to do this in the heft eventually). When I do so, the shower completes but it seems like none of my events have e's or mu's in the final state, as one would expect from a tau decaying leptonically. Reading around, it seems as though MG doesn't deal with tau decay and leaves that for pythia. It also seems like pythia by default has tau's being stable and therefor not decaying. I tried to remedy this by adding "MDCY(C15,1) = 1" to my pythia card but the end result seems the same. What do I need to do to get the tau's to decay properly?

Here is my pythia card as is:
##################################################################
!...Parton showering on or off
      MSTP(61)=1
      MSTP(71)=1

!...Fragmentation/hadronization on or off
      MSTJ(1)=1

!...Multiple interactions on or off
      MSTP(81)=20

!...Tau set to unstable
      MDCY(C15,1)=0

!...Don't stop execution after 10 errors
      MSTU(21)=1

!...PDFset if MG set not supported by pythia-pgs package (set in lhapdf5 or higher)
      LHAID= 10041

    LHAPATH=/users/lynchg/MG5_aMC_v2_4_2/pythia-pgs/src/PDFsets
################################################################

It seems like most (if not all) of my events are ending up with a final state of a number of gluons (two to four) and an electron neutrino.

Thanks very much for any pointers as to what to do.