When you compile a project with some link errors, the error messages run out of the window and destroy the original windows border.You have to resize the whole IDE to restore the bottom windows.
I can't reproduce...
May be it is a special case only happens with the chinese Win7 OS,so forget the bug report.
Tested again after switch to English language of win7 os,every thing is OK.I guess it is a bug from os since the same case happens to other softwares.