Comment # 8 on bug 1046104 from Dr. Werner Fink

(In reply to Robert Munteanu from comment #7)
> I upgraded myself and the issue is not fixed with the latest
> adobe-sourcecodepro-fonts package.
> 

Then the question rises: What happens if you're switching to the

   SourceCodePro-Light

font ...

Beside this it could also a problem with mkfontscale(1) as the messages are
from mkfontscale