my $h = unserialize($data); 
print ref($h), $/;
[download]

That'll tell you the reference type.

On another note -- I don't know the package you're using and it might be fine but it hits a couple pet peeves of mine (lower case package names are reserved for pragmata and if it's decent, production quality code, it should be on the CPAN).

I have used this in a couple of projects: PHP::Serialization. It worked great and it's even got some patches applied since and a new, solid maintainer attached.