Doh! It seems that Apache::Template (the mod_perl interface for Template Toolkit and a cool looking module) isn’t compatible with mod_perl 1.99 and Apache 2.0.x.
Having had a chance to read through most of the new Template Toolkit book from O’Reilly, I have to admit that it’s far more impressive than I first realised. Extra plugins and filters can be written and added into the basic templating system to provide extra functionality that doesn’t come as standard.
It’s just typical. I wait a couple of months for the new Template Toolkit book from O’Reilly to appear on Safari (the online bookshelf) and then when I give in and buy the paper copy it appears on Safari a few days later.