Hi bro.
I have installed omnet 4.2 in both machines. I don't really know what is crashing down with omnet plotting graphic tool, but I already have the same problem, I have tried to graphic throughput with a simple example but it doesn't works. Today morning I was thinking about the problem:
One of my hipothesis is:
rolling back omnet 4.2 to omnet 4.1 cause few moths ago I did the same test and it worked without problems, so, I guess its about the new omnet release.
The second one:
Yesterday I was not able to display the graphics using omnet IDE (running and compiling) , but instead of compiling the .ned files into IDE, I compiled and ran it in a mingenv.cmd terminal, once it did it. I used omnet IDE to show the results and somehow it was able to display the results.
However there is another problem, when your project shared a library (for example: inet, queueinglib or some library else), I still working in that problem trying to solve that situation.
Best Regards.
P.D. I forgot to tell you I have installed omnet in a windows 64-bits machine, so I have a ubuntu 11.10 distribution too.