Firefox issues with image uploads.
This may simply be on my end, as Firefox can give me an odd issue.
Uploading images with Firefox seems to be hit and miss.
For all purposes, it claims I have successfully completed an upload, however, the image does not come up in the gallery at any time afterwards.
I tried Chrome today and had no issues, so will keep an eye on that and use Chrome in the future.
Just thought I'd mention it in case it was site side and not a local issue.