Bug introduced in 10.0.0 and fixed in 10.0.2
Normally, you can enable Graphics3D to show tick marks by doing this:
Graphics3D[Sphere[], Axes -> True] 
But in Mathematica version 10, when I add an Inset which contains a Grid or Column, the output looks wrong:
Graphics3D[Sphere[], Axes -> True, Epilog -> Inset[Column[{"a"}], {.05, .05}]] 
The ticks only appear when I manually rotate the graphics or start editing the input line. But note that I produced the enclosed images here by doing Export["file.png",%] after each plot, so that this faulty display is indeed not just a notebook display problem - it leads to incorrectly exported graphics, too.
This doesn't appear to happen when the inset contains a Row instead of Column. I also see this strange behavior when doing something like this:
Plot3D[1, {x, -1, 1}, {y, -1, 1}, Epilog -> Inset[Column[{"a"}], {.05, .05}]] 
Here, you can see that the tick marks are displayed only partially!
My operating system is Mac OS X 10.8.5, and I am wondering if this is reproducible on other systems. If so, it would be nice to know how to work around this problem. The issue also goes away when the Inset only contains numbers and not strings.
Edit
I've reported this as a bug (CASE:1384605).



Grid, but it doesn't happen withInset["a", {.05, .05}]$\endgroup$