Highlighting in full-text search works case sensitiv

If you search for something in APEX you can use in version 4.x or later the full-text search.
It's a great feature, but the the word is only highlighted, if you write it completly the same way, even if you don't check "case sensitive".

Keep in mind that the result always finds all the correct words and only misses the red highlighted string.

Result when searching for P1600_AEU_WHRG_KEY

Result when searching for P1600_aeu_whrg_key