Nope it isn't just for you, it was a problem a while ago, but since the Support Forum gets cleaned out every few weeks, it has probably been lost.
To quote Rom
Arena Mode was the v1.3 patch. The v1.2 patch wasn't publicly released because it was the German gold master.
There are still three closed captioning bugs that we are looking at.
The first is lines that aren't appearing in some foreign languages. We managed to fix some of those in the v1.3 patch, but not all for a variety of reasons.
The second is that we have a system in place where a line is randomly selected. Unfortunately, only a single closed caption line plays for any of those lines. Fixing this one is extremely tricky.
The third is the closed captions during the end credits. The lines start out captioned, but at some point, the sounds transition into the music channel and music cues don't play closed captions. The lines are tagged correctly as non-music, but it doesn't seem to matter.
We haven't forgotten.
So basically you will have to wait for the 1.3 patch and make sure SinEpisodes has been set to update in Steam.