Dan,
I have no idea what is wrong, but reading your mail left me with a couple
of questions that may help others help you.

1) Is this a program that is working perfectly at other locations?
2) Has there been any changes to the code recently?

This will rule out things like doing DDL through code giving the "too many
versions" or something error.

3) Does the error always occur when working on the same data?

We only know that your problem occurs at the 27th execution every time. We
do not know if every execution is independant of other executions or if
there is a particular sequence. I assume the error always occurs when
working with a set table, but is it dependent on which record it
reads/modifies?

4) What version of IBO? Server? Is forced writes on? IB_Query or IBOQuery?

By the way, with IBO it is not necessary to call Open before calling First
(at least not when using native components). Try removing the call to Open
and see if that makes any change.

Set