我最近将我的上网本从 Ubuntu 11.04 升级到了 12.04 LTS。自从升级以来 - 事实上，可能是从升级到 11.10 以来 - 系统不再将触摸板点击视为鼠标点击（奇怪的是，除了在几个非常有限的情况下）。此功能在 11.04 中运行良好（在此之前，在基于 Jaunty 的 Eeebuntu 中），我无法习惯没有它的情况下工作。其他高级触摸板选项，如双指滚动，运行良好。
在系统设置中启用了“使用触摸板启用鼠标点击”。在 GPointing 设备设置 GUI 中，点击同样显示为启用状态。以下是“synclient”的输出：
Parameter settings:
LeftEdge = 1775
RightEdge = 5505
TopEdge = 1648
BottomEdge = 4602
FingerLow = 25
FingerHigh = 30
FingerPress = 256
MaxTapTime = 350
MaxTapMove = 350
MaxDoubleTapTime = 180
SingleTapTimeout = 180
ClickTime = 100
FastTaps = 0
EmulateMidButtonTime = 75
EmulateTwoFingerMinZ = 282
EmulateTwoFingerMinW = 7
VertScrollDelta = 110
HorizScrollDelta = 110
VertEdgeScroll = 0
HorizEdgeScroll = 0
CornerCoasting = 0
VertTwoFingerScroll = 1
HorizTwoFingerScroll = 1
MinSpeed = 1
MaxSpeed = 1.75
AccelFactor = 0.0361598
TrackstickSpeed = 40
EdgeMotionMinZ = 30
EdgeMotionMaxZ = 160
EdgeMotionMinSpeed = 1
EdgeMotionMaxSpeed = 442
EdgeMotionUseAlways = 0
TouchpadOff = 0
LockedDrags = 1
LockedDragTimeout = 550
RTCornerButton = 0
RBCornerButton = 0
LTCornerButton = -70
LBCornerButton = 8
TapButton1 = 0
TapButton2 = 0
TapButton3 = 0
ClickFinger1 = 0
ClickFinger2 = 0
ClickFinger3 = 0
CircularScrolling = 0
CircScrollDelta = 0.1
CircScrollTrigger = 0
CircularPad = 0
PalmDetect = 0
PalmMinWidth = 10
PalmMinZ = 200
CoastingSpeed = 20
CoastingFriction = 50
PressureMotionMinZ = 30
PressureMotionMaxZ = 160
PressureMotionMinFactor = 1
PressureMotionMaxFactor = 1
ResolutionDetect = 1
GrabEventDevice = 1
TapAndDragGesture = 1
AreaLeftEdge = 0
AreaRightEdge = 0
AreaTopEdge = 0
AreaBottomEdge = 0
HorizHysteresis = 27
VertHysteresis = 27
ClickPad = 0
现在奇怪的是：“synclient TapButton1=1”没有任何效果。我可以设置其他变量，但不能设置 TapButton1、TapButton2 或 TapButton3。
出了什么问题？如何修复？