Sitecore Publishing Service Field Casing

There is a bug confirmed by Sitecore support for version 2.2.1 (revision 180807) of the publishing service, where changes to fields where the only change is the casing of the field value are not promoted to publishing targets. This is a bit of an edge case but it can manifest itself if for example you are storing class/assembly names and newing up objects using Sitecore's ReflectionUtil:

Now let's say someone went against class naming conventions and created a class called JSONParser and then down the line that class got renamed to JsonParser, well the publishing service would not promote that change to your publishing targets and object instantiation on the delivery servers would begin to fail.

The issue is due to the collation of the database (Latin1_General_CI_AS).

They did supply a working patch that is pretty straight forward to apply, you only need to modify the publishing service itself (1 dll, 1 xml config). Support ticket number 290996.