Dapper - Edgy Update screen area Issues

[NoOp]

On my main system I finally bit the bullet and upgraded from Dapper to
Edgy in preparation for the eventual upgrade to Feisty.  6 hours later
all seems to be working; had to install the Feisty version of sysinfo,
and still sorting out some minor issues, but overall it's working.

I have an odd situation at startup however. When the final gnome screen
comes up I have a postage stamp size area of the screen in the upper
left hand corner that doesn't render properly. The area looks like a
barcode with vertical grey & white lines.

I've found, quite by accident, that if I open a terminal window the area
is still there. However, as soon as I type a character into the terminal
window the area clears and that portion of the screen renders properly.
>From there on out it seems to be fine... until I reboot again.

Anyone heard of this anything like this?