Annoying Typeface Mixing in Dim Style

Does anyone know what is going on here? I have my dimension style typeface set to Knockout Heavyweight. After many weeks of working on a file, eventually a different typeface creeps in (usually Agency FB), like you can see in the attached image. Does anyone have any idea why this might be happening?

Very odd and not something I’ve seen before.
Does the oddness change with the Zoom magnification or does it stay?
Does it look right using a different font face?

The zoom magnification doesn’t seem to be important to changing this behavior. The typeface that I observe this with is Knockout, but well, that’s pretty much the typeface I always use…

Since Rhino doesn’t supply any fonts; it just uses the Windows fonts installed on your computer, there isn’t much we can do.
I suspect you are using a damaged font. Do you see this problem on other Rhino computers with that font? If not, you may have a damaged font file that can be replaced.

Thanks John, this helps me troubleshoot.