Hi Folks,
I've downloaded and installed the beta version 1.9.0.885 for Windows.
I found that this version opens RAF files uncompressed and lossless compressed also, the black bar on the right hand side that is an issue in Version 1.8.5.703 wasn't there.
There was a slight problem with the rendering, so I restarted my laptop and tried again, and again it happened the best way I can describe this is if you say open an image add a new layer colour it black and then turn the opacity down to about 80% this affected about a quarter of the image. However, when I clicked on the develop button it rendered the image with no issues at all, by comparisons the lossless version didn't didn't display this affect.
On opening the uncompressed version again for a 3rd time, the rending issue wasn't present however I'm fully aware that this is a beta version but thought I'd add it here for the benefit of others, you may or may not experience these issues.
I would say just to sit it tight until the the final stable release comes out, for me it's no deal breaker as there are ways around this as I mentioned in a earlier post.
Thanks to @walt.farrell for the heads up on this.