Why is my Macbook Pro 2011 video garbled after sleep?

Question

Occasionally when I open my new (April 2011) Macbook Pro I'm greeted by an unusable system with a garbled display. Most often I have to force a reboot (hold down power button for 10+ seconds), but occasionally it will fix itself if I close the lid and re-open it.

• What is the problem, or what should I look at to find the problem?
• Are there other things I could try to wake this laptop from this state?
• I can't reliably reproduce the problem, so it doesn't seem that taking it to the genius bar is going to yield useful results, but tell me if I'm making a bad assumption here and I should take it back.

System info:

• MacBookPro8,3
• ATI Radeon HD 6750M
• Intel HD Graphics 3000
• If anything else is relevant, let me know and I'll post it. It's a standard 17" MBP, though I've added memory (notably this problem did occur prior to adding memory as well)