Forum OpenACS Q&A: problems with lang::util::localize

i have some problems with message keys not being translated to catalog-texts properly. here is an example:

set text {
<a href="/">Main Site</a> : <a href="/dotlrn/"><span>#</span>tlf-basic.dotlrn#</a>:
<a href="/dotlrn/classes/"><span>#</span>dotlrn.classes_pretty_plural#</a> : <span>#</span>dotlrn.classes_pretty_plural#
}

set html "Text 1: [lang::util::localize $text]\n"

set text {
<a href="/">Main Site</a> : <a href="/dotlrn/"><span>#</span>tlf-basic.dotlrn#</a> : Verwalten
}

append html "Text 2: [lang::util::localize $text]\n"

ns_return 200 "text/plain" $html

-------------------------------------------

this code produces:

Text 1: 
<a href="/">Main Site</a> : <a href="/dotlrn/"><span>#</span>tlf-basic.dotlrn#</a> : 
<a href="/dotlrn/classes/"><span>#</span>dotlrn.classes_pretty_plural#</a> : Kursvorlagen

Text 2: 
<a href="/">Main Site</a> : <a href="/dotlrn/">Mein Portal</a> : Verwalten
-------------------------------------------

as you can see, some message keys are translated and others are not (in text 2 the key <span>#</span>tlf-basic.dotlrn# is substituted, but in text 1 it is not). i had a look at lang::util::localize which i think is responsible for that but could not find the problem. does anyone had similar problems and more experience with lang::util::localize?

thanks, peter