[Virtualacorn-list] display collapse

[Bob Ardler]

For over a week the whole-screen RiscOS display has been collapsing
here, once or more per session, replaced by an empty window on a
Windows background. A grey rectangle appears in the bottom LH corner
of the screen, just above the icon bar. Clicking on it restores the
RiscOS window and open files/etc , but unsaved work is lost.

The machine is a Shuttle from RComp running RO 4.02 on Windows7,
professional. The collapses began the day after Windows sent the
notice of January support-withdrawal from W7 (re which Andrew
Rawnsley advised not to worry).

Is this collapse a known fault with a known remedy? (Andrew's
advice seems to imply that planned/programmed obsolescence is
not involved). And what on earth is that 1cm by 3cm unlabelled
grey rectangle?
--
Bob
PS: The March-April PDF advice brought 99.99% improvement.