Sorry, but StartIsBack does not affect that.
As stated, not a SIB issue. But to offer some help, check your startup items / startup folder. Possibly a shortcut for "Explorer" or "explorer.exe" has been added there. Located in Windows 7/8: C:\Users\%YOUR USER NAME%\AppData\Roaming\Microsoft\Windows\Start Menu\Programs\Startup or C:\ProgramData\Microsoft\Windows\Start Menu\Programs\StartUp Failing that another startup program is forcing the directory to load.