I have enhanced infotype 0001 and added one more field, while changing standard program i have choosen Maintained LogOn Language Option. Now while running PA30 Transaction some of field's lables are coming in German Language instead of English.
It might be a problem with missing english translations. Go to the main program you did the change in - go to the text symbols and check the translation. Those which do not have a translation into english or showing the german text in the translation field you need to adjust.