[TYPO3-mvc] translation bug in TYPO3 v6?

[Domi]

Hello again,

next problem in my upgrade task is the translation handling of my travel 
extension. This worked in TYPO3 v 4.7 and not any more in 6.x.

In default language everything works, but now I switch to english and my 
search and lists are not working anymore. The reason is, that I filter 
my travels with lets say category country.

Südafrika -> orig UID = 4
South Africa -> translated UID = 50

My searchbox controller generates now in a selectbox as following:
<option value="4">Südafrika</option>
<option value="4">South Africa</option>

So far so good, everything like in 4.7.
BUT in 4.7 in english I get a result of all travels, in 6.x the result 
is NULL.

Now I found out that the query works in one special case:
Bali -> orig UID = 5
No translation in english
-> now the search query finds all Bali travels in both languages.

Here the raw output of the MySql query which seems to lead into the bug:

http://pastebin.com/Cs67HY3N
I guess that this leads into the wrong query result:
http://pastebin.com/cGA8t4Fu
If I delete this lines my query works as expected.

Can somebody tell me if this is a bug? And if there is any fix for that, 
otherwise I'd file a bug report.

Regards,
Dominic