I think that loading the module with "do" instead of "require" will give you the control you're looking for. I've never tried it, but from "perldoc -f do" it looks pretty simple:

 do EXPR Uses the value of EXPR as a filename and executes the contents
         of the file as a Perl script. Its primary use is to include
         subroutines from a Perl subroutine library.

             do 'stat.pl';

         is just like

             eval `cat stat.pl`;

         except that it's more efficient and concise, keeps track of the
         current filename for error messages, searches the @INC
         libraries, and updates %INC if the file is found. See
         "Predefined Names" in perlvar for these variables. It also
         differs in that code evaluated with "do FILENAME" cannot see
         lexicals in the enclosing scope; "eval STRING" does. It's the
         same, however, in that it does reparse the file every time you
         call it, so you probably don't want to do this inside a loop.

         If "do" cannot read the file, it returns undef and sets $! to
         the error. If "do" can read the file but cannot compile it, it
         returns undef and sets an error message in $@. If the file is
         successfully compiled, "do" returns the value of the last
         expression evaluated.

         Note that inclusion of library modules is better done with the
         "use" and "require" operators, which also do automatic error
         checking and raise an exception if there's a problem.

         You might like to use "do" to read in a program configuration
         file. Manual error checking can be done this way:

             # read in config files: system first, then user
             for $file ("/share/prog/defaults.rc",
                        "$ENV{HOME}/.someprogrc")
            {
                 unless ($return = do $file) {
                     warn "couldn't parse $file: $@" if $@;
                     warn "couldn't do $file: $!"    unless defined $return;
                     warn "couldn't run $file"       unless $return;
                 }
             }

Just out of curiosity, why would the second attempt work? Are you modifying the file before retrying? Is it a configuration file or something?