Images are too big on calendar

Hello,

Weird things going with the images on my calendar page.

My client uploads a small image – this page has the correct size displaying: http://myartoncanvas.com/events/st-joseph-county-united-way-fundraiser/

But, this is how the same event displays on the calendar: http://myartoncanvas.com/calendar/ (go to October). The calendar display is blowing it up and they instead should be thumbnails. Or, even more ideally, the individual event should be bigger and the calendar should be more like a thumbnail.

Can you help, please?

Thank you!