I have 2 monitors which can rotate physically. They are working fine right now as non-mirrored, dual monitors.
I went to System -> Preference -> Monitors and tried to rotate the screens. As soon as I click Apply, I appear at the log in screen as if I just logged out.
Does anybody know what might be going on?
Here are some lines that might be relevant in /var/log/Xorg.0.log.
(--) PCI:*(0:1:0:0) 1002:9552:1458:21ac ATI Technologies Inc M92 LP [Mobility Radeon HD 4300 Series] rev 0, Mem @ 0xd0000000/268435456, 0xfe9f0000/65536, I/O @ 0x0000c000/256, BIOS @ 0x????????/131072
...
(--) RADEON(0): Chipset: "ATI Mobility Radeon 4300 Series" (ChipID = 0x9552)
...
(II) RADEON(0): RandR 1.2 enabled, ignore the following RandR disabled message.
(--) RandR disabled
There's also the gdm3 service running if that helps.