I use Google Calendar. I mark events that I've attended and done with the "check-mark in the green circle" icon, which is part of the Event Flair lab. But it seems that only Internet Explorer will let me do so without any problems. With other browsers I've used, including Google Chrome, Opera, Firefox, I can't "check off" my events without running into the dreaded "Error downloading event." message.

Aside from using Internet Explorer, what can I do to be able to check off my events problem-free?