I looked in the release notes and did not notice anything, but I compiled one of my apps with 1.6.4 and I noticed that the oncreate event for the forms is not behaving the same as before, it seemed in prior releases that the oncreate was the first thing to fire, now objects on the form are being created first before the oncreate fires.
or it's an issue with tcombobox firing the onchange event with no items to add.
Not sure yet, but the app ran fine yesterday when built with 1.6.2.