Pure speculation, but try replacing the logo....
I tried already without the logo. The design uses graphics which have been successfully placed many times as they are standing items.
The issue seems to be to do with text box resizing as it now has happened on another page with no logo. The only difference in the system setup is the use of ID6 and Lion OS8.
Sometimes frames just "go bad" and replacing the entire frame can fix the problem -- even if it worked previously or on another page.
Thank you for the advice.
In twenty four years of using Macs and Adobe software, I've seen and fixed most glitches but this one has me puzzled. I'll recreate the file from scratch, hopefully that will clear the bug.