Task Submission Bug

We have come across a bug when submitting a task for a ticket. Once we fill in all the relevant information for the task and add it, the systems begins to submit and then the header of the site flashes and sticks for a couple of seconds. What follows is a blanks screen with the wheels spinning. I have to click at the end of the URL and hit enter, then it takes me to the ticket and shows the task submitted. Please see the screenshot of the momentary flash of the "site within the site."

I switched to the sandbox theme and same thing happened (see screen shot). We have only modified the CSS in the theme. (As a side note: AC's most recent update has thrown in some extra span tags that cause issues with CSS-see other screen shot on the "add" button. We have work arounds but not the best solution.)