While waiting for the umpteenth disk reconstruction recently I came across this knowledge base article on Apple's site. They indicate it may cause some inconvenient problems. For me it's cost the data on the disk several times. The incompatibility seems to cause the master data block on the disk to be so corrupted that the only recourse is to begin anew. I'd love to do as the article suggests and call Canon. I wonder when I'll get a response? The problem seems to be primarily the ZR-40, ZR-45 and ZR-50 cameras.