mind actually linking that thread?

This is the original (under 1.78). This is the later one (under 1.79pr1).

Are you certain you don't still have Bomb Blokes' custom font installed? it's known to be incompatible

He says he's disabled it, and his screenshots do appear to be at the lower resolution. I've also released a new version which he says does much the same thing.

@silver07 Have you tried updating your graphics drivers? I have a feeling this is caused by non-POT texture shenanigans, but that's just a wild guess.

So here's the deal:
The original bug was caused by the use of NPOT textures, and very old graphics cards not supporting them. The solution to that was to revert to a square POT texture, which fixed the bug for everyone who originally reported it. Your bug seems to be something different, and nobody else has reported it except you. There's nothing unusal about the font rendering anymore (it's just a 256x256 texture), so i'm clueless for ideas to how to fix this. I suspect it's something unique to your setup, but I can't think what. Can you try creating a completely new Minecraft install?

@silver07 Your card was launched in 2004, so it's 12 years old, even. In addition, AMD are known for making suboptimal OpenGL drivers. They have improved over the years but your GPU likely only supports ancient versions of the driver.

One change that was made in Minecraft 1.8 was the introduction of VBOs being used for rendering. Coincidentally, 2004 is roughly the time when VBOs were added to OpenGL, so you could imagine that your drivers might have a buggy implementation. Try turning off "Use VBOs" in video settings.

Though, I recommend you just use a newer GPU, since nobody will be bothered to fix a bug that only happens on 12 year old hardware.

As this issue seems to be unique to you, on very old hardware, and there's no obvious problem in the code, i'm going toclose this bug as "cannot reproduce". Sorry