How to stop jitters?

[joe at actionline.com]

I have two computers using the same monitor, keyboard, and mouse with a
kvm switch. The image quality on one is perfect, but when I switch to the
other computer the monitor image is "jittery" whenever I move the mouse or
when viewing certain applications.

What can I do to stop these jitters?

Below are some of the specs from 'lshw'

 Desktop Computer: EX259AA-ABA s7520n
HP Pavilion 061 - version: 0nx1104RE101OPAL 00 - serial: CNH6241ZNS NA670
width: 32 bits
capabilities: smbios-2.4 dmi-2.4 smp-1.4 smp
configuration: boot=normal chassis=desktop cpus=1
uuid=80BD0E62-0469-1110-8433-E43F0BA8A58B

Motherboard
       product: Opal
       vendor: ASUSTek Computer INC.
       physical id: 0
       version: 1.02
       serial: MB-1234567890
     *-firmware
          description: BIOS
          vendor: Phoenix Technologies, LTD
          physical id: 0
          version: 3.04 (03/14/2006)
          size: 128KiB
          capacity: 448KiB
          capabilities: isa pci pnp apm upgrade shadowing cdboot
bootselect socketedrom edd int13floppy360 int13floppy1200
int13floppy720 int13floppy2880 int5printscreen int9keyboard
int14serial int17printer int10video acpi usb agp ls120boot
zipboot biosbootspecification netboot
     *-cpu
          description: CPU
          product: AMD Turion(tm) 64 Mobile Technology ML-34
          vendor: Advanced Micro Devices [AMD]
          physical id: 4
          bus info: cpu at 0
          version: 15.4.2
          slot: Socket 754
          size: 800MHz
          capacity: 3700MHz
          width: 64 bits
          clock: 200MHz
          capabilities: boot fpu fpu_exception wp vme de pse tsc msr pae
mce cx8 apic sep mtrr pge mca cmov pat pse36 clflush mmx fxsr
sse sse2 syscall nx mmxext fxsr_opt x86-64 3dnowext 3dnow up pni
lahf_lm cpufreq
        *-cache:0
             description: L1 cache
             physical id: 8
             slot: L1 Cache
             size: 128KiB
             capacity: 128KiB
             capabilities: synchronous internal write-back data
        *-cache:1
             description: L2 cache
             physical id: 9
             slot: L2 Cache
             size: 1MiB
             capacity: 1MiB
             capabilities: synchronous internal write-back unified
     *-memory
          description: System Memory
          physical id: 1b
          slot: System board or motherboard
          size: 1GiB
          capacity: 1GiB

     *-pci:0
          description: Host bridge
          product: RS480 Host Bridge
          vendor: ATI Technologies Inc
          physical id: 100
          bus info: pci at 0000:00:00.0
          version: 10
          width: 32 bits
          clock: 66MHz
          configuration: latency=64
        *-pci:0
             description: PCI bridge
             product: RS480 PCI Bridge
             vendor: ATI Technologies Inc
             physical id: 1
             bus info: pci at 0000:00:01.0
             version: 00
             width: 32 bits
             clock: 66MHz
             capabilities: pci ht normal_decode bus_master cap_list
           *-display UNCLAIMED
                description: VGA compatible controller
                product: RS480 [Radeon Xpress 200G Series]
                vendor: ATI Technologies Inc
                physical id: 5
                bus info: pci at 0000:01:05.0
                version: 00
                width: 32 bits
                clock: 66MHz
                capabilities: pm vga_controller bus_master cap_list
                configuration: latency=64 mingnt=8