Q: I am very frustrated with iTunes Store

Two days ago, I tried to rent a movie in iTunes (V10.6, the latest one) on my MacBook Air and failed with an unknown error 5002'. iTunes asked me to try to rent the movie later. After googling the problem without any luck, I finally decided to use my windows 7 laptop, which is running iTunes 10.5.3.3, and succeeded with the same Apple ID. Though it's possible that the different behaviors of iTunes on Mac or PC may be due to its different versions, the fact that, in this case, it's PC that got the job done, still surprised me. Given iTunes is originally designed and programmed to be more compatible and smooth with Mac, it's so ridiculous that renting a movie on Mac crippled it.

And the story continued today. I tried to rent another movie using the mac and I found this after I went through the purchase:

This happened after I downloaded 8 MB of the movie. In the first accident, error 5002 happened before I could finish the purchase. Now I have already rent the movie but not able to download it. I think Apple is violating its 30-day period policy during which you can watch the movie because of this error. I don't think my Apple ID has problems since I can buy music from iTunes.

I am using the newest MacBook Air, the newest Mac OS X (Lion), the newest version of iTunes but having the worst USER EXPERIENCE. I just don't know what to say to Apple...