Previously BT5r1 auto-size guest display worked perfectly, however I did a distro upgrade from r1 to r2 and got problem doing auto resizing.
Well here’s how to do it:
this script is included with BT, great script for downloading linux kernel source codes. Executing this script will remove previous source code (linux 2.6.39-4) and download the current linux version source code.
2. Install guest addition with virtualbox.
3. Reboot and you are done.