It sounds like you are trying to flash a rom that hasn't been completely downloaded. Have you tried redownloading the rom and flashing it again?

It also seems like quite a few people have been getting the status 7 error. Which i have never experienced so i might not be of much help. The best thing i can always recommend is to go to the Q&A section on XDA and ask there. Every problem i have ever had with rooting has been solved on XDA.

Update nevermind, looks like you already asked this question on the NScollab thread. Someone should definitely be able to help you out there.

 

This usually happens to me when I choose apply updated zip file instead of install from sd, make sure you choose install from sd from the rom manager.