マウスポインタが画面の右に移動し続けるのはなぜですか？

マウスポインタが1分に1回モニターの右側に移動します。無効にしてもpsmouse同じことusbhidが発生したため、おそらくマウス/タッチパッドのハードウェア/ドライバの問題ではありません。どちらもありませんXorg.0.log。

Debian JessieとXFCEを実行しているLenovo W541に、次のように2つのモニタを設定しました。

$ xrandr
Screen 0: minimum 320 x 200, current 4480 x 1600, maximum 8192 x 8192
eDP1 connected 1920x1080+2560+0 (normal left inverted right x axis y axis) 344mm x 193mm
   1920x1080     60.06*+  59.93  
   1680x1050     59.95    59.88  
   1600x1024     60.17  
   1400x1050     59.98  
   1280x1024     60.02  
   1440x900      59.89  
   1280x960      60.00  
   1360x768      59.80    59.96  
   1152x864      60.00  
   1024x768      60.00  
   800x600       60.32    56.25  
   640x480       59.94  
VGA1 disconnected (normal left inverted right x axis y axis)
DP1 connected 2560x1600+0+0 (normal left inverted right x axis y axis) 641mm x 401mm
   2560x1600     59.97*+
   1920x1200     59.88  
   1920x1080     60.00    50.00    59.94    24.00    23.98  
   1920x1080i    60.00    50.00    59.94  
   1600x1200     60.00  
   1680x1050     59.95  
   1280x1024     75.02    60.02  
   1280x800      59.81  
   1152x864      75.00  
   1280x720      60.00    50.00    59.94  
   1024x768      75.08    60.00  
   800x600       75.00    60.32  
   720x576       50.00  
   720x480       60.01    60.00    59.94  
   640x480       75.00    60.00    59.94  
   720x400       70.08  
HDMI1 disconnected (normal left inverted right x axis y axis)
DP2 disconnected (normal left inverted right x axis y axis)
HDMI2 disconnected (normal left inverted right x axis y axis)

グラフィックカードの設定は次のとおりです。

$ lspci -v |grep -A9 VGA
00:02.0 VGA compatible controller: Intel Corporation 4th Gen Core Processor Integrated Graphics Controller (rev 06) (prog-if 00 [VGA controller])
        Subsystem: Lenovo Device 221e
        Flags: bus master, fast devsel, latency 0, IRQ 45
        Memory at b1400000 (64-bit, non-prefetchable) [size=4M]
        Memory at a0000000 (64-bit, prefetchable) [size=256M]
        I/O ports at 5000 [size=64]
        Expansion ROM at <unassigned> [disabled]
        Capabilities: <access denied>
        Kernel driver in use: i915

--
01:00.0 VGA compatible controller: NVIDIA Corporation GK107GLM [Quadro K1100M] (rev a1) (prog-if 00 [VGA controller])
        Subsystem: Lenovo Device 221e
        Flags: bus master, fast devsel, latency 0, IRQ 49
        Memory at b0000000 (32-bit, non-prefetchable) [size=16M]
        Memory at 80000000 (64-bit, prefetchable) [size=256M]
        Memory at 90000000 (64-bit, prefetchable) [size=32M]
        I/O ports at 4000 [size=128]
        Expansion ROM at b1000000 [disabled] [size=512K]
        Capabilities: <access denied>
        Kernel driver in use: nouveau

この問題の原因と解決策をご存知ですか？