Photopress disappears

Photopress disappears – does anybody know why photopress keeps disappearing from the plugin library? I install and activate it and everything is OK – then I come back the next day and it is not even on the plugin list. So I go to the files and discover that the folder is still there. In order to get it to work I have to overwrite the folder with the same files. and that gets me a day before it is gone again. Thanks, Chief