Missing figures report

[vEnhance]

Got the following email:

I noticed several minor glitches on page 398, 447, 843, 968 where images fails to load. Since this is such a valuable living document, I wanted to make sure you were aware of it.

Too busy the next few weeks to investigate it, but I'm going to throw this into the issue tracker so I don't forget about it later. (Also, if anyone wants to beat me to looking at this, I'd obviously be happy to have that happen.)