Just started again and for just a second I could see something like:
sda not a valid superblock magic
Maybe the raid assembling procedure is buggy? And therefor a following LVM setup may have problems to complete.
What kind of information is necessary to help you? Is it able to "switch" the initramfs in something like a debug mode? Some interactive mode whatever?
By the way: At the moment, I am running on x64_64. I do attahc a current log assembled with nvidia's bug tool (would be greeat to have such a script even for distros??)