I've had issues with my NAS recently corrupting a small number of files. File name still appears to exist but is zero bytes in size. I'm still researching as to the cause. This leads me to my question - how intelligent is the "Find Missing Photos" command in Lightroom 4? If the filename exists but is, for example, zero bytes in size, does Lightroom still see the corrupted file as present or does it flag it as "missing"? My library is over 25,000 in size and spans nearly two decades... I'd hate to unknowingly lose photos due to corruption. It's all backed up, but what's to say the backup hasn't overwritten a file with a corrupted version?