Using SQLDeveloper 2.1.1.64, if you try typing the following code:
DECLARE
v_status_code NUMBER;
v_status_text VARCHAR2(30);
v_to_delete NUMBER := 5;
BEGIN
PACKAGE_NAME.Delete(v_to_delete, v_status_code, v_status_text);
END;
Pressing Enter after the PACKAGE_NAME.Delete(...) line will make Delete go into all caps (DELETE). I have turned off Case Change in the SQL Formatter options but this still happens. I get other problems similar to this one, where it will randomly reformat lines of code, but I couldn't think of an example as consistent as this. The specific package name doesn't matter, and it does this even if PACKAGE_NAME is in UpperCamelCase.
I don't know if this is a bug with SQLDeveloper or if I'm missing some settings somewhere. It seems as though the SQL Formatter settings under Tools > Preferences > Database > SQL Formatter > Oracle Formatting don't do it, so I don't know what to do. It's getting annoying having to catch some of these format changes, which I sometimes only notice when doing a diff.