Event module seems to conflict with OG

A week or two ago I installed the Organic Groups (OG) module. This module allows users to be assigned to different groups. Each group has its own pseudo-homepage, and all material flagged as private to a given group, gets the theme of that group. Each group can have its own theme. This makes it easy to see what group's material you are looking at, should you be in more than one group. Group theme settings over-rode the settings of individuals as well as the site default.

Today I installed the event module. I made no other changes to the themes at all, nor did I touch the groups. But I noticed that suddenly, all group themes have reverted to the default value for the viewer. If you use the site's default, all group themes = the site's theme. If you go in and choose a different theme for yourself (different from the site default) then all group themes = your personal theme.

I can only surmise something in either the css or the .theme file or somewhere in event is making it over-ride the organic group setting, but I cannot figure out where this is or how to fix it. Any assistance would be appreciated.

Thanks,
Steve