Sporadic "no statement executing" error

Hi.  I have a CGI script that fails sporadically at a call to fetchrow_array
.

The code around the point of failure looks like this:

    $sth->execute( @param );

    while ( my @row = $sth->fetchrow_array ) {
      ...

The execute statement always succeeds without error (the RaiseError DBI
option is set to true).  Since there's no earlier error, I don't understand
why I'm getting the error "fetchrow_array failed: no statement executing".

Unfortunately, I have not been able to reproduce the error with a small
program.  Nor have I been able to find a way to reproduce the error
reliably.

What else can I do to troubleshoot this problem?

Thanks!

tlm