[Rivet] Herwig problem

[Adam Davison]

Hi,

I'm having a (probably unrelated) Herwig problem. Whenever I choose a 
diboson process, 2800, 2810 etc... then I get a crash:

           NUMBER OF SHOTS    =       10000

  HWWARN CALLED FROM SUBPROGRAM HWHGB1: CODE = 501
  RUN CANNOT CONTINUE

All I'm running here is:

agile-runmc -p IPROC=2800 Herwig:6.510

I also tried this in an old setup of rivet on a 32-bit slc4 machine at 
UCL and got exactly the same error, which makes me think this isn't a 
problem with my toolchain or architecture any more.

Are there any known issues with rivet here?

Adam