I have this same issue and it's really, really bad. It's extremely difficult for me to read things because so much of the letters are cut off.
I have had the same issue on a Powerbook G4 running Tiger, on a 15" Macbook Pro 2.8Ghz running 10.5.5 and 10.5.6. I have had it on an MBP 17" 2.93, and currently on an MBP 17" 3.06 running 10.5.8.
No matter if I fresh install everything including the OS, I can't get it to go away.
There is actually one other game I have seen this with, also an online game, it's called Deliantra and it's the exact same text issue. As if one or both edges of each letter is chopped off.