I can't find anything in ZK that would set icon distance to 100 on its own. What widgets are you using? Check your installed widgets for the strings 'UnitIconDist' and 'disticon'.
As far as I can tell there are two widgets with any capability of setting icon distance to 100. The first is epicmenu itself via a settings slider bar. It reads the default value from UnitIconDist in springsettings.cfg. The second is the widget 'Icon Zoom Transition', which handles icon distance itself but can only set it to 100 when shut down. On shutdown, it sets icon distance to the value reported by the slider bar in epicmenu. So in both cases the setting would have to start at 100.
I recently moved the widget 'Icon Zoom Transition' from Level 4 to Level 3 configuration(
https://zero-k.info/Forum/Thread/31189?postID=226780#226780 ). I changed some of its defaults to make its use more obvious and to more closely resemble the default icon distance of 151. If you were using some of the default settings for this widget, but not others, then you could have a weird combination of settings. This only affects people at Level 4 and above though, and there isn't anything in the widget called 'icon distance' that could be set to 60 or 100, so it doesn't sound like this is the issue.
