Error when try to add related term wich exists in different languages

Hi,

I found a bug in Taxonomy Manager wich makes it impossible to attach a related term under some specific conditions.
The attached Screenshot makes the problem visible.

1) We have a Term e.g. "péristyle" (french)
2) We have another term "véranda" (french) wich exists also in German but slightly different: "Veranda" (german). Uppercase first letter and no Accent.
3) You try to set "véranda" (french) as related term to "péristyle" (french) wich should work
4) You get the error "Error! Your last operation couldn't be performed because of following problem: Terms must be of the same language" wich is definitely wrong as obv. the terms are both in the same language.

I identified two possible reasons for this wrong behaviour:
1) Why is "Veranda" (german) in the autocomplete proposal at all? Shouldn't there be a language check in the first case and don't even show impossible different language terms for selection?
2) Something must be wrong in either the value of the second proposal "véranda" (french) or the function wich checks the language of the selection and outputs the error message.

It must be a bug in Taxonomy Manager because when i edit the Term on the Term detail page it works well...

Best Regards,
Sandro