I connect to my machine that's running Newsbin via Remote Desktop regularly, and find that posts that are not multi-part have a black square (with maybe one grey pixel?) next to them where the expand arrow would be on a post with multi-parts. Also, the colored sphere icons all look like they are within a black square. It's not a major bug, but it was disconcerting until I figured out that the black boxes were supposed to be transparent.
I find this to be the case when selecting either 24 bit or 32-bit graphics depth in the RDP client and can provide a screenshot if it would be helpful.
This was present in beta5, I updated to beta9 and find it to still be present.