I also came upon this issue recently. It not only affects umlaut characters but also accented characters such as á vs. Á
Just noticed this too, and was about to file a new bug report.

It is for all foreign characters. E.g. a search for "æøå" won't match a sentence with "Æøå" (uppercase Æ).



TextEdit.app has it correct:



Using ST3 3059.
I have posted a question here as well:
http://www.sublimetext.com/forum/viewtopic.php?f=3...

Hopefully someone has a workaround.