I may be totally off-base here, but this part of your code looked strange, and struck me as possibly being related to your problem -- it just doesn't seem right, in any case:

package test;
use gadget;
use vars qw($VERSION $CLASS);
$CLASS = __PACKAGE__;
$VERSION = "0.01";

BEGIN {
        @test::ISA = qw(gadget);
        @test::ISA = qw(Exporter);
        @test::EXPORT = qw(parse_tag);
}
[download]

First off, why put a BEGIN block inside a package? If you're going to load this as a module via "use test;", then the script that invokes this "use" statement is already handling the package within its own BEGIN block. If you're loading it with "require test;" then I think it's already too late for your package's BEGIN block to be heeded as such.

Second, I would have thought that the assignment to @ISA should go like this:

@ISA = qw/gadget Exporter/;
[download]

You're already in "package test" at this point, so having "@test::ISA" seems redundant. But the main point is that in the code you posted, the assignment of "Exporter" to @ISA would appear to replace (obliterate) the preceding assignment of "gadget" to that array.

I actually haven't had much practice with OO inheritance, but just in terms of basic Perl syntax, you may want to take a closer look at these things (and let me know if I'm wrong). Good luck.