In the 3D view for Hammer, all the textures and entity sprites appear blurry (like Hl2 would on low settings). I know its not meant to happen and there is no way to change texture quality settings within Hammer.
RabidMonkey linked me to a site earlier where a guys having the same problem, the one reply he got said that if he turned anti-alaising and anistropic off it works, but thats only for Nvidia cards, im using a Radeon 9800 pro (is there a way to turn of aa and antistropics for Raedon cards (normally its set to application prefference and there is no off button).
This problem started happening after the large Hammer update not too long ago. I just reinstalled Steam too hoping it would fix the problem - it obviously didn't. I just cant get rid of this and its making lining up textures a real bitch!
Here's a pic of my nasty prob:
http://img452.imageshack.us/img452/173/blurryhammer0qp.jpg