u character problem on RS/6000

[Wendy Ross]

Has anyone else noticed a very bizarre problem that seems to
come up about every three months with the "u" character?
 
For example, when the "u" is typed, it appears on the line,
but is then stripped before interpreted.
su
s: command not found (or something like that).
cd /usr
/sr is not found either.
However, cd /*sr does work.
 
The strange thing is that it only seems to happen irregularly.
It seems partially tied to a pty.  For example, the "u" won't
work, but if you telnet back into the same machine from itself
(luckily telnet doesn't contain a "u") then the "u" character
will work just fine.  When exiting from the telnet session to
the original session, we are right back to the "u" character dilemma.
 
I cannot reproduce this at will, which is why I hesitate to
call IBM defect support.  It just seems to "happen" every once
in awhile.  So far the cure has been rebooting the machine, and
everything is fine.
 
This has occurred under Golden and 3001 so far.  Last time all
ten of my lab machines had this happen at the same time.
 
Has *anybody* else noticed this problem?  Am I the only one
experiencing this weirdness?
 
Thanks for any suggestions, consolation, or messages just plain
saying "you're weird, you have weird machines; no-one else has
ever seen, heard of, or dreamt of this one before!"
 
Wendy Ross                   wross at caen.engin.umich.edu
Computer Aided Engineering Network
University of Michigan
 
<No this is not a joke!>