I have a strong suspicion that book uses mod_perl 1.x. You can get that version of mod_perl to work with perl 5.6.1, so there shouldn't be any huge problems collecting the parts that you need. You can find detailed instructions here.

If all else fails, and you still want mod_perl 1.x, try downloading Indigoperl 5.6.1. It is fully compatible with ActivePerl 5.6.1, apart for PPM which has been substituted by a web interface, and comes with Apache and mod_perl 1.