There is no known bug. Are you trying to include a location image? Maybe this has something to do with it. If you can't sort it out, submit a ticket with all of the details you are trying to save for your location... a login that has access to this on the frontend... and we'll check it out.
I seem to be having the same problem - with DT Reg 2.7.8. Interestingly I did not have the problem on the test site with DT Reg 2.7.7a, so it is probably some configuration issue - did you discover anything that might help me?
I should have added that when I click on Save (front-end) I receive a Location Saved message but the new location does not appear in the location list.