Host:
Windows 8.1
Intel HD Graphics 4600 (24/04/2014 10.18.10.3574 up to date)
3200x1800 Primary Display
1680x1050 Secondary Display
VirtualBox 4.3.20r96997
Guest:
Windows 8.1
VirtualBox Graphics Adapter for Windows 8 21/11/2014 4.3.20.0
Guest Additions 4.3.20r96996 (1 digit less than host version)
Problem:
With Auto-resize Guest Display enabled, if the (maximized) window is in the
- Primary monitor, the guest shows an "effective" display size of 3200x1608. Correct. (after allowing for header and footer)
- Secondary monitor, the guest shows an "effective" display size of 3360x1980. Fail. This is a very fuzzy display (unusable of course) as the physical pixel count for this display is only 1680x990 (after allowing for header and footer). Something has got lost (gained?) in translation.
I will try reverting to an earlier release to see if that helps.
Update: same phenomenon on 4.3.18