I did a simple Drop Shadow using the default text object and then went to move it. It was very slow and jerky redrawing and when it finally settled down it left this artifact behind.

That's a known problem. If you can use OpenGL that doesn't happen.

I do have the OpenGL check box selected so I assume that's all I need to do. Admittedly I do have an old AMD 6700 card so maybe that's part of the problem.

Also, I did discover that I had an instance of Visual Studio running so I shut it down, restarted but got about the same result again with only Krita open. I also think that this build has been noticeably slower in some respects. In fact I just did a small lasso select in a paint layer and when I was through with it I couldn't get it to deselect. Then I started doing all kinds of things to try and free it up and was about to kill the process when...not only did it free up but most of the stuff in the buffer kicked in and started hitting the screen. I ended up with a mess of unwanted strokes (stupid of me) but I've never seen Krita behave like this.

The opengl/non-opengl thing is about artefacts left behind by the green selection box. This issue looks more like an artefact in the update code for the psd layer styles, and probably is a real bug that Dmitry has to look into.