I saw that there are some problems in Lion with NTFS disks, I don't know if there is a link with the fact that you can't run bootcamp. There are many bugs in the transition from Snow Leopard to Lion. So maybe if you retry to install your bootcamp partition from scratch, it might work. I hope that you have saved all your files of your bootcamp partition before upgrading to Lion. First of all open the disk utility, go to your bootcamp partition, and click "repaire permission". And then try to reboot your computer on the bootcamp partition. If it doesn't work, what I can suggest you is if you have enough free space on your HD, don't delete your "bootcamp partition", maybe a Lion upgrade will fix that issue, and retry a bootcamp installation from scratch.
Moreover I have a big problem too in Lion, nobody replied to my question so maybe you can help me. When I run an external hard disk, my mac does recognize it, I can open a couple a folder inside, and then the finder crash, until I unplug manually the hard disk. They used to work fine on snow leopard a week ago. Strangly, my time machine works, but it's quite slow... Maybe if you have an external disk, can you tell me if everything works fine