When using an Outline FX with Alignment set to Inside or Centre any movement of the Radius slider results in the object (a rectangle etc.) being immediately filled with whatever Outline color you have set
This only occurs with OpenCL enabled.
My video card is a NVIDIA GeForce GTX 660 - not sure if this is a specific video card related problem so others may want to check and see what happens to them.
My Benchmark specs are in the Benchmark thread which also highlighted a small anomaly in those results - not sure if there is any correlation.
This bug occurs in all 3 of the 1.9 beta apps (Windows 8.1)