problem with usrsuwev

Dear colleagues

When analysing FLUKA binary activation result files with the usrsuwev
program a strange result occurred:

I have 5 binary output files which I process with usrsuwev. The usrsuwev
and the activation binary files are based on the FLUKA version: FLUKA2010
Version 2.0 Sep-10.
I received a very high activation value (irradiation time 1 day, cooling
1day) with a very high error (99%), which could be traced back to the
nuclide Sn-121. I omitted one of the files resulting in a much lower
activation value with a very small error. Believing that I have a strong
fluctuation in the file which I omitted I thought the problem is
understood. However, when I looked up the production of the two sets of
calculations (5 files versus 4 files) I found out that in both cases the
production is identical (within 3%) with an error of 2%. Also the
production of isotopes in the same mass region, which might lead to Sn-121
by decay, are similar in both cases. Could you please explain how it is
possible that we get very different activation results (factor 1E5) in
these two cases although we have in both cases similar nuclide production
rates.

For the cooling time of 0s the discrepancy is even larger (several isotopes).

I attach a tar file with two scripts, one running the usrsuwev with 4
files the other one with 5 files. Moreover the 5 binary files and the
results
are attached.

Thanks in advance for the answer

Best regards
Helmut