Discovered this while taking the rhce exam, actually. I did a custom install, and used Select Individual Packages. I removed most of the sgml stuff, but apparently missed some. The unresolved deps window came up, saying that something or other depended on jade. I didn't want to spend more time on it, so I just let it install what it wanted to satisfy the dependencies. This didn't work, however. It installed jade, but not sgml-common upon which jade depends (in fact, it's a prereq). So, the jade package failed to install properly. My guess is that the check-deps code is forgetting to go the extra step of checking dependency information for the packages it suggests. I haven't looked at the code though. (I'm not yet proficient in Python.) It might be relevant to note that this was using the text-based interface.
hmmm ... I tried a base install (no package groups selected) and added jade individually...when prompted for the dependencies screen (ie jade depends on sgml-common), I chose "Install to satisfy dependencies" ... upon reboot both jade and sgml-common were installed ... please let me know the exact package selection you tried that made this fail, and we'll try to reproduce it and reopen the issue ... thanks for your report!
Since I was under pressure at the time, I don't have an exact record of what was installed. I know that the sgml stuff was chosen by whatever components I picked -- I removed things from the list rather than adding. I'm not sure that should make a difference, though. I'll see if I can cause it to happen again, and I'll reopen this if I can.