Hi, sorry to creep on this it just popped up as we were getting things back up to speed following our spin out as our own company.
It sounds like you were experiencing a verification scan (I can send the link once I've made more than 5 posts or if you google "Is my backup restarting CrashPlan" it should be the first link). It can appear as though the data suddenly isn't backed up but it's a byproduct of the way that we do our deduplication and the data is stored securely the entire time.
I'm sorry for the confusion and please let me know if there's any other information I can provide or the support team would be happy to help as well.
Cheers,
Riley