date & time at top of screen

[mja!aramini]

Lately on my 3B-1 with 3.51 software the part of the line of text at the very
top of the screen where the date and time are usually displayed, there instead
will be a strip of stippled background pattern.  When this happens, logging
out and back in again doesn't help, but rebooting does bring the date and time
back, for a while at least, but eventually (like on the order of several hours)
the date and time will disappear and are replaced by the stippled background
pattern again.

In addition to the date and time disappearing, when that area of the display
turns into a stippled pattern, the envelope icon doesn't come up when I have
e-mail.

Can anyone shed some light on what may be going on here?

Is there something I can do to bring the date and time back when it disappears
that is less drastic than rebooting?

-Michael Aramini
 3B-1 at home:  ...!apollo!mja!aramini
 work:  aramini at apollo.com  -or-  ...!apollo!aramini