accessing local table

I have a form with lots of tables that work just fine, including
adding, posting, etc.

I added another table to use as a key field so that each record
in another table would be unique. It has one record, and one
of the fields is 'max_id'.

So, as a test I made a button and try to set the value
of max_id to (for example) 2. I get that the table is not
in the right mode to change (basically the program crashes
with an access denied message).

I've looked at the properties of this table over and over
and can't find anything wrong, or different than all the
other tables that work just fine. Nor could a friend of
mine.

There is no code of mine that sets the value this way.

When I first boot up, the database desktop can access and
restructure the table fine - but after this error, delphi
itself seems to lock the table so that I have to exit
delphi and go back in before the database desktop can even
re-structure the table: indications taht something is indeed
setting this property.

Some times I even have to re-boot - and this is odd because
I'm running NT 4.0, not Win 95.

This occurs both on NT 4.0 and NT 3.51.

Help!!! I no longer know where to even suspect.
Thanks in advance.

--
   "You know, I used to think it awful that life was so unfair. Then I
thought...wouldn't it be much worse if life were fair and all the
terrible
things that happen to us come because  we actually deserved them.
    "So now I take great comfort in the general hostility and unfairness
of the universe."

(From B5 "A Late Delivery From Avalon")