Currently Being ModeratedSep 4, 2013 9:06 AM (in response to Barry)
Currently Being ModeratedSep 4, 2013 9:14 PM (in response to Linc Davis)
Thanks for the pointer. Neither of the Adobe plug-ins mentioned in the linked discussion are installed on my MBP; in fact the only one installed is the Google Earth We Plug-in.
In the meantime, the mouse pointer has gone back to behaving normally. The only significant action I can think of is that the MBP was shut down for a little over 10 hours today. I had restarted it a couple of times last night, but had not let it sit for any extended time.
Still a mystery.