KVM oddities on PRERELEASE 7.1 with X.org 7.3 and Wmaker

[Scott Spare]

Hello,
I'm seeing erratic USB mouse behavior in X.org with a KVM switch:

-The mouse pointer is jumpy in X.org when moused is enabled and with
/dev/sysmouse set as the input device in xorg.conf.
So I disabled it...
- Disabling moused and using /dev/ums0 as the input device causes mouse
freeze on switch instead of the randomness; the mouse is redetected as ums0
each time the KVM is switched.  But if the KVM is switched when graphical
vTTY is up, the mouse pointer will freeze.
-If I select any of the non-graphical virtual TTYs (i.e. ttyv0-7 using
CTRL-ALT F1 to 8), then go back to the graphical vtty, (CTRL-ALT F9), the
mouse pointer unfreezes.

The keyboard has no trouble - I think it's using some kind of PS2 emulation
through BIOS(?)  But the mouse definitely freezes every time.  Is this an
Xorg problem??

Possibly related info from the list:
usb/102096: /usr/sbin/usbd does not handle multiple devices in one
event<http://lists.freebsd.org/mailman/htdig/freebsd-usb/2006-August/002470.html>
http://lists.freebsd.org/mailman/htdig/freebsd-usb/2005-July/001213.html

How to reproduce:
Attach a USB KVM switch, and switch machines while Xorg is running.
Possibly could reproduce by disconnecting and reconnecting USB mouse on
running Xorg

Notes about the KVM switch:
-It has 4 ports, but has only one USB connector per machine connection.  In
other words, it has 4 USB-A plug connectors, even though it takes care of
both keyboard and mouse.  I guess it acts like a hub in that respect.
-The other machines connected to the KVM re-detect the kb and mouse each
time the switch is switched.  (e.g. WinXP does its BeeBoop - detected
hardware

System info:
FreeBSD 7.1-PRERELEASE FreeBSD 7.1-PRERELEASE #0: Mon Nov 10 02:00:54 EST
2008
CPU: Pentium III/Pentium III Xeon/Celeron (596.00-MHz 686-class CPU)
real memory  = 402653184 (384 MB)
avail memory = 375795712 (358 MB)
pcib0: <Intel 82443BX (440 BX) host to PCI bridge> pcibus 0 on motherboard
uhci0: <Intel 82371AB/EB (PIIX4) USB controller> port 0xcce0-0xccff irq 11
at device 7.2 on pci0

usb0: <Intel 82371AB/EB (PIIX4) USB controller> on uhci0
usb0: USB revision 1.0
uhub0: <Intel UHCI root hub, class 9/0, rev 1.00/1.00, addr 1> on usb0
uhub0: 2 ports with 2 removable, self powered

ums0: <Logitech USB-PS/2 Optical Mouse, class 0/0, rev 2.00/22.00, addr 4>
on uhub1
ums0: 8 buttons and Z dir.
ums0: at uhub1 port 4 (addr 4) disconnected
ums0: detached

KVM switch:
IOGEAR GCS634U 4 port USB KVM Switch

Maybe I need to ditch the KVM?  Go back to PS2 mice?