Hello, just registered to see if anyone can help me with an issue I've been having. I downloaded Ubuntu 12.04 64bit a few days ago, and I have to say, I love it. The only thing that has been giving me an issue is Steam. Whenever I launch Portal 2, the game crashes at the first loading screen, before the main menu. I'm running it with the newest version of Wine, and haven't been able to find a solution on their site. The Steam client itself has been working fine, besides occasionally locking up. Sometimes after it crashes, Steam gives me an error message saying something like "Launch failed (Application running)". It doesn't always give an error message, sometimes it just crashes and doesn't react to it. I haven't tried any other games yet, I don't own any other ones. Anyone know a way to get the game running?

System specs below, in case that they would help find the cause of the problem:

MSI H77MA-G43 Motherboard
Radeon 7770 GPU
Intel i5 2500 CPU
8 GB of RAM

I only have Ubuntu installed on the hard drive, no other operating systems.