virtualbox.org

64-bit guest, Xubuntu.
32-bit host, Vista.
Had been functioning perfectly for weeks, only change I remember making was giving it more RAM.

I've checked visualization extensions enabled in the BIOS.
I've created a new VM with a new hard drive, same problem.
I've enabled and disabled ACPI APIC-IO, NX, nested paging, and 3D acceleration.

I will check the VM on another 64-bit machine and if I can, I will try a 32-bit guest.

Thanks in advance.

VM and host hardware are fine, I can boot the guest under Fedora 10 64-bit.

Should I raise a defect?

Same problem here!
I have a VM (Ubuntu 9.04 64bit) that was running fine on both Linux (Ubuntu 9.04 32bit) et Windows (XP 32bit) host. But yesterday evening I upgraded VirtualBox on Windows to the latest version (3.0.6) and this morning, I cannot start the VM...
I have several other VM and they seem to work (I did not test them all, but I have a Ubuntu 9.10 Alpha 6 32bit which is working fine).

It seems that Windows 32bit host with a Linux 64bit guest does not work any longer with latest VBox release (3.0.6), it worked fine with the previous release, and it is working fine with Linux 32bit host + VBox 3.0.6.

I'm using the VirtualBox release from the VirtualBox website, not the OSE version.

I have found a bug related to this problem: Bug #4947 (http://www.virtualbox.org/ticket/4947)

Sorry for the silence, was on holiday.

I've updated to 3.0.8 and the problem seems to have gone away