i dont know how and when this happen but i got this issue now for the third time!

within last 3 month there where 3 User accounts wich lost there already uploaded and added images fom image folders. i asked them..hey did you deleted your older images from mediamanager? and they all said no we did!
so i think this happens probably during upload, i'v checked there image folders and they contain after upload only the latest uploaded images and the older images not longer exists. also i checked the image code in Blog Post and there was everything ok, except the images was not longer on server!
i know this issue will be hard to replicate but why should get 3 different User the same issue if there are not a bug..