I have a Lenovo ThinkVision LT1421 USB DisplayLink monitor. I have successfully been able to use it under Fedora as it simply appears in KDE's display control panel as DVI-1 which I can then enable. I am on a clean insall of Arch with KDE, when I connect the device, it appears as /dev/fb1 and the output of dmesg is...
[ 632.417667] udlfb: DisplayLink Lenovo LT1421 wide - serial #6VDK9242
[ 632.417672] udlfb: vid_17e9&pid_03e0&rev_0108 driver's dlfb_data struct at ffff8801ffc80000
[ 632.417675] udlfb: console enable=1
[ 632.417676] udlfb: fb_defio enable=1
[ 632.417678] udlfb: shadow enable=1
[ 632.417870] udlfb: vendor descriptor length:17 data:17 5f 01 0015 05 00 01 03 00 04
[ 632.417874] udlfb: DL chip limited to 1500000 pixel modes
[ 632.417906] udlfb: allocated 4 65024 byte urbs
[ 632.501649] udlfb: 1366x768 @ 60 Hz valid mode
[ 632.501654] udlfb: Reallocating framebuffer. Addresses will change!
[ 632.502578] udlfb: 1366x768 @ 60 Hz valid mode
[ 632.502580] udlfb: set_par mode 1366x768
[ 632.504044] udlfb: DisplayLink USB device /dev/fb1 attached. 1366x768 resolution. Using 4104K framebuffer memory
Despite this, it does not appear under KDE's display options so I can't enable it. I have spend ages looking around online for a solution but most of the tutorials seem to be out of date as they mention installing packages that as far as I'm aware are not part of the kernel. It seems odd to me that it isn't working as the monitor does seem to be detected and worked out of the box under Fedora 18.
Any help would be greatly appreciated as this is really thie only thing that is stopping me from being able to use Arch as my full-time OS.
Thanks in advance,