Unfortunately, the blocky text bug it turns out is actually a fairly major nvidia driver bug with respect to GeForce 6600 and 6800:
If your card isn't one of these, please let me know.
Anyhow, basically I read about it on a guild wars forum:
Newer drivers might fix it (I'm not sure if NV has addressed this yet) but older ones might too. If you decide to downgrade (and I couldn't blame you if you didn't want to) then these ones might do it:
I wish I could offer a better solution for you! But for now it looks like NV will have to fix this. Please let me know if you try newer drivers and get it to work, however. Also, you don't have a GeForce 6600 or 6800 then definitely let me know, since it might be something else.