using macbook air touchpad scrolling is unusable in a way that 2-finger scroll basically does page up/down.
i'm guessing that "Scrolling Distance" which is limited to 10.0 mm is somehow related to this issue.

$ sudo dmidecode |grep -A3 'System Info'
System Information
        Manufacturer: Apple Inc.
        Product Name: MacBookAir5,2
        Version: 1.0

$ lspci
00:00.0 Host bridge: Intel Corporation Core Processor DRAM Controller (rev 18)
00:01.0 PCI bridge: Intel Corporation Core Processor PCI Express x16 Root Port (rev 18)
00:1a.0 USB controller: Intel Corporation 5 Series/3400 Series Chipset USB Universal Host Controller (rev 06)
00:1a.7 USB controller: Intel Corporation 5 Series/3400 Series Chipset USB2 Enhanced Host Controller (rev 06)
00:1b.0 Audio device: Intel Corporation 5 Series/3400 Series Chipset High Definition Audio (rev 06)
00:1c.0 PCI bridge: Intel Corporation 5 Series/3400 Series Chipset PCI Express Root Port 1 (rev 06)
00:1c.1 PCI bridge: Intel Corporation 5 Series/3400 Series Chipset PCI Express Root Port 2 (rev 06)
00:1c.2 PCI bridge: Intel Corporation 5 Series/3400 Series Chipset PCI Express Root Port 3 (rev 06)
00:1d.0 USB controller: Intel Corporation 5 Series/3400 Series Chipset USB Universal Host Controller (rev 06)
00:1d.7 USB controller: Intel Corporation 5 Series/3400 Series Chipset USB2 Enhanced Host Controller (rev 06)
00:1e.0 PCI bridge: Intel Corporation 82801 PCI Bridge (rev a6)
00:1f.0 ISA bridge: Intel Corporation 5 Series Chipset LPC Interface Controller (rev 06)
00:1f.2 SATA controller: Intel Corporation 5 Series/3400 Series Chipset 6 port SATA AHCI Controller (rev 06)
00:1f.3 SMBus: Intel Corporation 5 Series/3400 Series Chipset SMBus Controller (rev 06)
00:1f.6 Signal processing controller: Intel Corporation 5 Series/3400 Series Chipset Thermal Subsystem (rev 06)
01:00.0 VGA compatible controller: Advanced Micro Devices, Inc. [AMD/ATI] Madison [Mobility Radeon HD 5730 / 6570M]
01:00.1 Audio device: Advanced Micro Devices, Inc. [AMD/ATI] Redwood HDMI Audio [Radeon HD 5000 Series]
02:00.0 Ethernet controller: Broadcom Corporation NetXtreme BCM5764M Gigabit Ethernet PCIe (rev 10)
03:00.0 Network controller: Qualcomm Atheros AR928X Wireless Network Adapter (PCI-Express) (rev 01)
04:00.0 PCI bridge: Texas Instruments XIO2213A/B/XIO2221 PCI Express to PCI Bridge [Cheetah Express] (rev 01)
05:00.0 FireWire (IEEE 1394): Texas Instruments XIO2213A/B/XIO2221 IEEE-1394b OHCI Controller [Cheetah Express] (rev 01)
ff:00.0 Host bridge: Intel Corporation Core Processor QuickPath Architecture Generic Non-core Registers (rev 05)
ff:00.1 Host bridge: Intel Corporation Core Processor QuickPath Architecture System Address Decoder (rev 05)
ff:02.0 Host bridge: Intel Corporation Core Processor QPI Link 0 (rev 05)
ff:02.1 Host bridge: Intel Corporation Core Processor QPI Physical 0 (rev 05)
ff:02.2 Host bridge: Intel Corporation Core Processor Reserved (rev 05)
ff:02.3 Host bridge: Intel Corporation Core Processor Reserved (rev 05)


Reproducible: Always

Steps to Reproduce:
1. clean kubuntu 14.04 install on MacBookAir5,2
2. start scrolling
Actual Results:  
scrolling is too sensitive

Expected Results:  
normal scrolling