Hi Emily,If I remember correctly Jeb said via twitter that this issue would be fixed in 1.6.2.
It's either what Fred said, or because the HD Texture Support in 1.6.1 is broken and\or does not support HD Fonts. When Optifine is released, try using it to fix your problem.
This is not a bug, this is a known caveat in 1.6.1.
Hi Emily,
If I remember correctly Jeb said via twitter that this issue would be fixed in 1.6.2.