[Grhm]

Hi, all.
This may not be an issue with Fastmail at all, but perhaps the effect of some arcane thing about file names that I don't understand, but...
Earlier this evening I uploaded seven photographs so that I could publish them using Fastmail's excellent (and, I suspect, scandalously under-used) photo-gallery web-site facility.
After they had been uploaded, the file-names of all but one of them had changed.
I had re-named them all in the local file system to reflect their content but, after uploading, only one of them retained that name; the other six had new, generic-looking names beginning 'IMG_'
It seems particularly strange that it only happened to six out of the seven files.
Does anybody have any ideas why this may have happened, and/or how I can avoid it happening again?
Thanks,
Graham.

ADDENDUM - NEW INFO
It appears that the change of name happened not as the files were uploaded to Fastmail, as I had thought, but as they were bluetoothed from one device to another prior to being uploaded.
This means that Fastmail is in the clear, and is definitely not the culprit!
I'm still mystified by it, though, and would value anyone's opinion of what the cause might be.