When using multiple channels in a single window, irssi appends the channel name to the nick thusly:
This carries over into the log file, in spite of the fact that it's completely pointless in the default autolog configuration (as each channel gets it's own logfile regardless).
Pisg parses these incorrectly, believeing that the :#example is part of the nick. So rgubele shows up twice, as:
in the stats output.
This may be configurable in irssi. I haven't researched it because it doesn't matter; I have lots of logfiles like this and I'm too lazy to write a script to go through and fix them all. Easier to alter pisg to handle it.