I love my Amazon Kindle. I love reading with it, I love how light it is, and I love the battery life. I also love the fact that it automatically syncs with the Amazon Kindle application on my iPhone and iPod touch. That means any book will open to the last page read regardless of the device last used. it is an amazing bit of technology that makes reading books across multiple platforms beyond simple.It’s a perfect situation — right? Well, it’s an almost perfect situation. This afternoon I discovered a huge Achilles heel in the whole Amazon Kindle environment.Perhaps the best way for me to explain the problem is by simply recounting the events that led to the discovery.Two days ago I upgraded my iPod touch to iPhone OS version 3.0. Today my new iPhone came. That means two new handhelds in a three-day period. I loaded all of my primary apps onto both and began the process of entering my credentials for each app that requires them. (I decided it was best to start off with a clean slate rather than attempting to restore from a prior backup.)When I got the Amazon Kindle app I knew there was one particular book I needed to download to both devices immediately. It’s a reference book that I wanted to make sure that I had on my device as the weekend began. But when I opened the app it only showed me a small subset of my books. “What?” I wondered. I went into that digital download portion of Amazon store and there I saw a list of all the books that I have purchased for my Kindle. “Great,” I thought “I’ll just choose the books that I want and click the ‘ download/send it to…’ Button next to the item.” I clicked and a few books gave back the message “successfully sent to”. A number of the books, however, including the one I was looking for, gave back the message that they were unable to be sent to my iPhone. I tried to download it to my iPod touch and received the same message.Figuring that the store might not be recognizing the two new devices I removed all of my handheld devices from my account and added both my iPhone and my touch back. I went back in, clicked “download/send to” and received exactly the same message. I was starting to get frustrated.At this point I decided that I’d spent enough time trying to hassle with this and, since I must doing something very simple wrong, my best alternative was to simply call customer service. I did and that’s when I got the surprise.The customer rep asked me to send every one of the books in my Amazon library to my iPhone. Most of them gave the message that they were sent but a number of them returned the message “Cannot be sent to selected device”.“Oh that’s the problem,” he said “if some of the books will download and the others won’t it means that you’ve reached the maximum number of times you can download the book.”I asked him what that meant since the books I needed to download weren’t currently on any device because I had wiped those devices clean and simply wanted to reinstall. He proceeded to tell me that there is always a limit to the number of times you can download a given book. Sometimes, he said, it’s five or six times but at other times it may only be once or twice.And, here’s the kicker folks, once you reach the cap you need to repurchase the book if you want to download it again.Quick aside — all of the books that are in my Fictionwise bookshelf having been downloaded numerous times and although I have to go through the pain of unlocking them each and every time, I’m able to download them to any iPhone or iPod touch I’m using without a problem. It’s the reason that I’ve been using Stanza, now owned by Amazon, a fair bit these days as I read through some of the books remaining in my account.It gets worse.