How do I fix my boot-looping Samsung Galaxy Tab 10.1?
I had the very same problem with my IO tablet (samsung logo loop, sometimes the upload_cause screen, but never actualy booted). Took me a lot of try/fails before I found a working solution. And this is it: You have to reflash not only the stock rom, but the stock bootloader too. I followed this tutorial and my tablet is working without a hitch! Good luck!

http://rootzwiki.com/topic/2525-guide-wi-fi-flashing-stock-bootloader-to-io-tab/