Did you use the "1.1.0.6 Updater" from 1.1.0.4, or did you use the setup "hl1106.exe" and do a full install?
I'd recommend reinstalling Half-Life, and then Counter-Strike. If you have the retail Counter-Strike CD then I'd recommend reinstalling that. CS is known to have problems like this - usually a reinstallation cures the problem.