Like several others in this topic I'm also having the "black screen" issue in the Elder Client. I've tried the updated 32-bit and 64-bit version, disabled tripple buffering in CCC, disabled the Windows firewall and my router's, changed my Catalyst drivers from 12.6 to 12.4 and tried "direct connect" and "browser settings" in the JAVA CP, but I'm still getting a black screen after I've connected in the client. The original client takes forever to download, no matter if I try to start the game through the "play" button in the top or by downloading the file from the PAQ.
Since I've reconfigured my router a few days back in order to get a cell phone to connect to my Wifi network, it might well be the problem lies there. The last time I played H&H is a few months back, however, so I can't be sure it's indeed the router. Are there any specific router settings or features which might interfere here? The router I'm using is a D-Link DIR-655 (1.31EU firmware, revision A4), so if there's anyone with that same model who can connect, I'd be very interested to know how that router's set up.
Edit: I've now tested the standard client on two other systems (one running W7 X64, the other XP SP3) and it worked on the latter, so I think I can rule out the router.
Edit2: After reinstalling Firefox and Java 32-bit (7 update 5) the Elder client still gave me a black screen. Then I downgraded Java to some random older version (6 update 30) and now it's working!