And possibly found a bug.  I'm stuck in Lambda Core and I know the last time I played HL I got further than this.  I can't figure out what to do next so I got bored and started chucking grenades through the window.  All of the sudden the screen fades to black like something is happening then you see the words "Subject: Freeman..." then it appears to load a level only to put me right back with all my grenades again and all of the barrels I blew up are back but all the monster models are still dead.  Anyone know how to proceed?  It's patched to a fairly recent version.  Here are some screenies: