The latest update from steam to stop the Ad-Killer in CS has also broken the Hl1 games with Steambuster Rev.
A temporary fix is available for this problem.
If your copy of HalfLife or blueShift keeps quitting to the desktop when run through steambuster then download this file
ad killer? you dont need that. you can use a method i used. and works in msot servers. its like only works in d2. it just covers up the adds with the patterns of the walls