Thanks for your bug report. Unfortunately I have not been able to reproduce this issue so far. I tested by entering several lines into the editbox, some of which were single lines and some of which were multiple lines. I then pressed the up key to scroll up through the lines. This worked until I reached a multiline entry, at which point the control+up key combination was required. Once I reached a single line entry again, I was able to use just the up key.
