I was using the mod Mo Glass with the possibilty to create glass slabs, but when it turned them in to a multiblock it losses all it's translucentcy. Don't know if you can fix this or not, seems minor.

Last time I checked, this was a limitation of LibMultipart. I can take a look whether I can fix this now, though, since LMP might have gotten the functionality I need. Also, duplicate of #4.