Does this mean my CompactFlash is faulty?

[ATJ]

I just got home from a dive where I took around 150 photos. All the photos got stored OK, but there is something odd about how they are on the card.

Instead of just a single 100NCD70 directory, there are also 101NCD70, 102NCD70 and 103NCD70. The first lot of photos are in 100NCD70, but it includes a zero length DSC_6752. 101NCD70 and 102NCD70 just have the zero length DSC_6752. 103NCD70 has the full DSC_6752 and then all the rest of the photos from the dive.

I'm guessing that the camera tried to write to the card and hit an error and kept creating new directories until it could write. This has happened once before and may have been the same card. I can't be sure as I have 2 SanDisk ultra II 1.0GB card. I'll mark this one so I know next time.