dual monitor breaks when not config'd for builtin monitor is to the left of second monitor

[Michael Hohnbaum]

Upgraded from 13.10 to 14.04 on my dual monitor system. System consists of a system76 laptop (built in monitor is 1920x1080 resolution) and an external monitor (ASUS 1920x1080 resolution).

Prior to the upgrade, the monitors were configured with the ASUS monitor above the laptop monitor. After the upgrade, the monitor configuration reverted to be configured with the laptop on the left (ASUS on the right). When I use the Settings->Display tool to move the monitors to the previous configuration, it is no longer possible to move windows between the monitors or to move the cursor between the monitors. This did work fine previously, so is a regression. I have tried several other configurations, and none seem to work other than the default.

One other note, I use synergy to provide keyboard and mouse from my desktop system (i.e., the laptop is the client). This works fine, but since it does affect the mouse thought worth mentioning in case there was some interaction from that involved.

[uhon.ch (uhon)]

Same problem here. Attached external Monitors (different monitors and resolutions tested) through VGA or DP on my Notebook i experience problems with the mentioned screen placement.
The above screen works perfectly as long as the cursor stays on that screen. Wen I move the cursor down to the built-in screen, the above monitor starts to scroll between the screens.
I'm unable to move a window down to the built-in screen. Window-Title-Bar seems to hang at the bottom of the screen, also the rest of the window is shown on the other screen.

this short video demonstrates the problem: https://www.youtube.com/watch?v=7Qlkpe2MpNk

I once experienced this scrolling effect also horizontally (monitor to the right), but this happened only for a single screen session.

Editing ~/.config/monitors.xml manually resulted in the same problem, also when screens were placed using xrandr.
I also changed primary monitor (in monitors.xml) to the external one, but that had also no effect.

Sidenote (may or may not be important): I'm using nvidia-prima, which enables me to switch between graphics cars.
My System is a Lenovo Thinkpad T430 with two graphic cards a.k.a. nvidia optimus (DP wired to Nvidia 5400M and VGA wired to and Onboard Intel-Graphics Chip), problem happens on both ports.

[Michael Hohnbaum (hohnbaum)]

An update: I disabled synergy, set the monitor configuration to the desired format and it worked. Re-enabled synergy and all is happy now. Have been through multiple reboot cycles and the monitor config is ok.

So for my case, this appears to be an interaction problem with synergy and monitor configuration, with a fairly easy workaround.