Five issues when using VirtualBox 4.3.12

[robpats]

I have five issues when using VirtualBox 4.3.12.
The host is Windows 7 64-bit and the guest is XP 32-bit.

1. VM is suspended after disk full. I free some space and then resume the VM but it hangs. The VM window is not responsive.
2. When I press Host(Right Ctrl)+P to resume a suspended VM, it resumes and then sometimes shutdowns.
The log is lost so no log can be provided.
3. VirtualBox creates a new differencing disk after creating/restoring a snapshot.
If the new differencing disk is moved/deleted and then restore the snapshot, VirtualBox.exe eats up a CPU core.
It does not exit even when the window is closed. I have to kill it in the task manager.
4. A 3D acceleration enabled VM which have run Direct3D application sometimes crashes when it shutdowns.
5. A 3D acceleration enabled VM which is running Direct3D application always crashes after the host wakes from sleep.

Any help is appreciated.