[doob]

I never would have guessed init_language had anything to do with phrases...

It turns out the problem was actually to do with php syntax when converting the templates into php echo statements. PHP doesn't apparently like echoing the variables from the templates, so I needed to chop up the echo into smaller bits so that instead of echoing something like

echo onFocus="if (this.value == \'$vbphrase[username]\') this.value = \'\';" />

it reads

echo onFocus="if (this.value == \'' . $vbphrase['username'] . '\') this.value = \'\';" />

So the problem was always just syntax! Slaps forhead.