I have a Debian (actually LMDE) guest on a Windows 7 host. Recently I updated the guest OS and got kernel 2.6.39. I have been unable to get seamless mode or auto-resize working with either the 486 or 686 variants of 2.6.39 and I have had to revert to 2.6.38. Reinstallation of guest additions under 2.6.39 produced no obvious errors, but it just disables those options in the view menu.
Is anyone else having this issue with VirtualBox and kernel 2.6.39?