I've attached some screens to give you an idea of what's going on (in addition to the following links).
Basically, I'm running steam in a separate VT because doing so resolves an inconsistent frame rate problem that I'm experiencing. More on that here:
When I switch between the two VTs running X, the text becomes what you see in the screenshots.
A fellow in the thread I linked suggested filing a bug report here. If that's what it's going to come down to, can someone direct me on the procedure?