Jon Peatfield wrote (3/14/2007 6:51 PM):
> I note that ')' and TAB differ by a single bit (0x29 versus 0x09). ...
> When you did something unrelated which used lots of memory/io that 
> might have cause it to get flushed and so appear to 'fix' things.

Ah, that's an excellent observation!  Yes, I think you must be right.  A 
memtest/memtest+ (and a full filesystem check too) will be the first 
thing on my agenda for tomorrow.  Thanks, all, for the excellent help.

    Best regards,
    Glenn.