[TYPO3-english] multilanguage issue in 6.0

[Domi]

Good Morning,

I have a very weird multilanguage issue. My website is running with 
newest powermail 2.0.5 and stable 6.0. After Ticking the 
Language->German flag the LLL language label are empty.

I checked the existence of the language.xml file, all looks right but 
the label remains empty:

10 = TEXT
10 {
  wrap = var JsValidationCheckCheckboxes = '|';
  data = 
LLL:EXT:powermail/Resources/Private/Language/locallang.xml:JsValidationCheckCheckboxes
}

How can it be that the typoscript language handling does not read out 
the label?

Thanks for any thoughts,

Dominic