I'm running HL2 on my MacBook Pro 15" 2.4Ghz. I installed Leopard last weekend and HL2 ran great all week. Until I reached Chapter 9a that is.
The first problem was a freeze on loading just before Gordon Freeman and Alyx meet up with Judith Mossman in Nova Prospekt. I got past this one by changing all of my video settings to low and changing them back after the load.
All was good again until the teleportation sequence in the next room where I get a freeze during the teleportation animation. This one occurs during gameplay, not during the load. I tried changing the settings and adding -nosound to the launch options, but no good. These are the launch options I've used so far: -novid -console -dxlevel 80
Thanks in advance for any suggestions.