Aero / transparency issues on MacBook Air

Hi there, I'm new to Parallels, I'm running the trial version on my MacBook Air to see if I like it, and I do, so I'm definitely going to purchase it.

I have two small quibbles though, and was wondering if someone on that Internet that you have now might be able to help me. I shall try to provide as much information as I can.

I have a late-2010 13.3" MacBook Air and last week installed the trial version of Parallels Desktop 6 for Mac. I installed a legitimate copy of Windows 7 Home Premium, and it works just fine.

The only thing that doesn't work is the Aero business (and with it, windows transparency effects and the ability to change window theme colours - I'm assuming they're connected).

Like I said, it's a minor quibble, and I've been around the forums and I can't find anything relating specifically to this. Some people are saying it's to do with outdated video graphics cards, but then other people will say that mine should be supported (NVIDIA GeForce 320M, according to System Profiler). I don't know if these features are not enabled because I'm only using a trial version of PD6? I don't see why that would be the case. Either way, I'm stumped.

The second minor quibble of mine is that - and I fully realise that this is not the right area of the forum to discuss this in, but anyway - is that you can't appear to update the free version of Chrome OS that you can download via PD6. Anyone know why that is?

Any help would be much appreciated!