I've used this module on Server 2008 64 bit successfully (32-bit Strawberry Perl 5.8 and 5.10 and same as pp-packed executable). There is nothing to take care about. The only problem is if you are using 32-bit application and try to access keys below
HKLM\Software
this access get redirected to
HKLM\Software\Wow6432Node
Maybe you want to check http://support.microsoft.com/kb/896459 and http://support.microsoft.com/kb/305097 for further information.
First try to check which version of perl you are running then check if the keys are available in the proper registry subkey.
Update:
There are some hints on the MSDN how to access the other "registry view" using VB amd WMI. It should be not such hard to rewrite it in perl. Look at this article: http://msdn.microsoft.com/en-us/library/aa393067(VS.85).aspx