PS/2 console mouse dysfunctional in FreeBSD 5.1

[Lee Hinkleman]

Dear freebsd-questions:
My Genius NetScroll+ PS/2 optical mouse was working fine in the console, and in KDE, with FreeBSD 4.7, but is not working in the newly installed FreeBSD 5.1 console.
KDE and X haven't been re-installed yet.
In /stand, and from ./sysinstall, and then from 'perform post install configuration', and then from the mouse configurator, I've tried several times to select the port as /dev/psm0 and the protocol as 'auto' or PS/2. When I test the mouse in the next step, the pointer is initially difficult to find and then, with mouse movement, appears as if delayed by about 3 seconds, but does seem to move to a reasonable position. While moving, the pointer disappears, and then it re-appears when the mouse is stationary.
Thanks for any clues.
Sincerely,
Lee Hinkleman