Solaris 10 Unable to use "Dumb" KVM (Avocent SwitchView USB 4-Port), Works Under Solaris 8

I have two Sun Blade 150 clients, one loaded with Solaris 8, the other
Solaris 10.

I noticed that if I put the clients on a "dumb" KVM (Avocent SwitchView USB
4-Port), that the Solaris 8 machine works when switching between KVM
channels (the /var/adm/messages log shows 20+ usb related events from
kernel and usba)

The Solaris 10 machine will not reconnect to the KVM, and I have to SSH
into the box and reboot it.

Anyone had similar experiences with USB keyboard/mice reconnect working
under  Solaris  8 and not under Solaris 10?

When I SSH into the misbehaving Solaris 10 machine and do a "cfgadm", I can
see that the USB devices have disconnected and will not reconnect, no
matter what combination of cfgadm commands I run through.  Only a reboot of
Solaris 10 fixes the problem.  A sub-optimal solution.

And yes, newer "smart" KVM's work (IOGear GCS1734), just not the older
"dumb" Avocent.

Any help is appreciated.

Brian