open $hash{'t'},"test.txt";
...
@lines = <$hash{'t'}>;

print @lines; # end up with a GLOB pointer, 
                    # not the contents of the file

close $hash{'t"];

##</code><code>##

open $hash{'t'},"test.txt";
$a = $hash{'t'};                 # pass the hash value 
                                        # to another scalar

@lines = <$a>;                # and suddenly grabbing the @lines 
print @lines;                     # results in correct output!
...