assertion failed: 'TheSessionId.theCnt <= 0'

Hi

when I try to run the polyclt (2.8.1) with options --unique_world no
--local_rng_seed 101, 
a Error occured.

--
UniqId.cc:32: assertion failed: 'TheSessionId.theCnt <= 0'
Aborted
--

What's wrong? 
If I don't use this options the test runs with my workload. 

The reporter don't create any image. I use the gnuplot (4.0.0-4). The error
message is:

error: cannot plot
/tmp/polyrep/Test-123/figures/populus.level.trace.scope=sides
=server__phases=top1,cold.gp; consult error messages above, if any
plot file was:
set term png color small
set output
'/tmp/polyrep/Test-123/figures/populus.level.trace.scope=sides=server
__phases=top1,cold.png'
set title ''
set grid
set linestyle 1 lt 3
set linestyle 2 lt 1
set linestyle 3 lt 2
set linestyle 4 lt 4
set size 1.0,0.5
set xlabel 'minutes'
set ylabel 'level, #'
plot '-' title 'agents' with lines
7.74397 1
8.74397 1
9.74397 1
10.744 1
11.744 1
12.744 1


should I use a other version of gnuplot?


kind regards

Tom Fischer