OK, so basically you should be seeing your description or summary (as I guess you realise) but for some reason it isn’t showing.
I took a look at this event:
http://community-buzz.com/event/read-and-pick-story-time-at-weavers-orchard-1000-a-m-every-wednesday-2/
I know you provided a description because the excerpt is visible when hovering over the event in the calendar. What I do notice, taking the above URL as an example, it that the area that ought to contain this description instead is completely taken up with various social media buttons.
If this isn’t the result of a conflict with the another plugin (or your theme – I see you stated that you checked both these things) then I can only imagine that this results from a change made to your templates – have you made any customizations to your events theme templates … and are you able to double check if this is a conflict with another plugin/your theme?
Thanks!