Well, the apostrophe phenomena is everywhere! 🙂
This time I found out that the tooltip when you over an RSS button does not show correctly if there is in apostrophe.
I was also thinking of checking more… and yes, it happens on many others too. I modified a few to add an apostrophe and as soon there is one, the string ends. “Quote’ this post and reply” become “Quote” and “View ed’it history” become “View ed”.
two things… first how did you change the strings?? you cannot just add a quote… unless you made sure you had balance quotes… ie ‘some string’y thing’ will cause problems and will be invalid… if you edit the string, you must change it to “some string’y thing”…
if you changed the translation string in the .mo file, then that would be fine…
I did make a bunch of changes (core and plugins) for tooltips that might have been translated… so if you could svn up and take a look, would be appreciated…
Looks fine to me! I see the only you haven’t modified is sp-profile-view-functions.php, maybe there is no occurence in this file. So, do you think that the apostrophe nightmare is now gone for good and something from the past? 
EDIT: wow, just been hit by a 500 error on complete simple-press domain. Not the first time this is happening. Glad I was lucky that the post was sent on refresh.