As I just told one of your engineers on the 'phone (and posted to various newsgroups/slashdot/etc.) I am concerned that there is a major problem with your (crappy - move backwards) installer, "anaconda". It crashes and dies horribly (sometimes with an oopps or sometimes with a panic, etc.) when it detects a cryptographic filesystem. I can ellaborate if necessary, but I think you a). probably ought to know already b). should have not let this happen c). can figure out how to rectify this soon. I look forward to hearing from you soon. Jon.
Please peovide more details of the failures which you are seeing, as that will help to recreate your specific failure in the test lab.
The partition stipulations have been relaxed in the latest installer, so hopefully that will help you out.