Bug: text editing can move textbox

After compiling 1.2 with difficulties on ubuntu 11.04, yes all dependencies were resolved eventually, and qtcreator gave 18 red (!) warnings and 300something yellow /!\ warnings it does run.
I found tonight that when editing in an tekstbox, like copyrights, when the cursor is moved right past the last character with the arrow key ->, or left before the first character using <-, the whole box moves to the side.

Would this be my compilers fault, or is there a bug in the program?