I'm experiencing a peculiar issue with the links in the calendar and message popups in Moodle 2.3.3 when I use Firefox.
If you go to the 'Go to messages' link, the page simply jumps a little and you are not directed to the Messaging page. Something similar is happening with the calendar popups. If I click on the link once, nothing happens, but if I activate the popup again and click on the link it takes me to the event page. The difference seems to be that you can immediately bring up the calendar popup once again but cannot do the same with the message popup.
We're not experiencing this problem in Chrome or IE. Interestingly I don't experience this problem in Firefox when I log into the Moodle forums. If I click on the message link it takes me straight to the messaging page. It must, therefore, be something to do with our particular system and Firefox. Does anyone have any idea what could be causing this?