Ok. On further review (would still like to see the test results), I wonder if there are one of two things going wrong. If either of these is a factor, we should document a temporary workaround and fix the bug:
1. Try selecting 'current' instead of 'month.' It is possible it is trying to calculate a month based on the dropdowns. You are entering dates manually, so you shouldn't need to select an interval. (If this fixes it, it is still a bug and we should fix it on our side too).
2. Try posting the transaction first. If this fixes the dropdowns, we need to fix this as well.
I am happy to file these on our sourceforge site on your behalf if we determine one is causing the problem, or you can. These would affect, likely, the rare cases where no transactions are entered and posted. I will be trying to test this today as well, but have a couple of other things on my plate first. I am not sure this would cause the issue with the dropdowns though.