Not that I use pisg, but you probably need to change the
Format value to be something like XChat or xchat (I don't even know if that is case sensitive to be sure). pisg is considering the kicks, joins, and parts to be actions, since they are in the form of "* nickname has been kicked from #channel by user (reason)" or otherwise starting with an asterisk. As pisg documentation states it supports XChats logging format, I suppose it can detect this relatively easily.
Visually, looks fine in XChat due to the use of colors, but colors aren't saved in the logs, so the similarity may be confusing to pisg. You could always use custom text events and create a new pisg log format, but that may be too much work.