XFree 4.0.1 upgrade problem: Mouse now a big blob?

[Graham Williams <Graham.Williams@cmis.csiro.au>]

I've just upgraded my "unstable" installation to use XFree 4.0.1
(previously XFree 3.3.6) on a neomagic-based laptop. I run Helix GNOME
and gdm with two displays active by default. Soon after installing I
was moving from one X display to the other (Ctl-Alt-F8) and suddenly
the mouse changed from the usual pointer to a roughly 1 inch square
blob!!!!!!  It's now basically a white square with black vertical
lines through it.... a bit like a bar code. Any ideas what could have
happened and how to fix?  I've rebooted, I've hunted around for image
masks, I've rapidly swapped between displays, I've run out of
ideas.....

Cheers,
Graham