We have a server with various websites where each website has a FTP user associated with FTP access to that website folder. One of our users every few weeks experiences difficulty logging in via FTP. When he brings up the problem to me, I try and sure enough, the FTP credentials no longer work. Logging into the server and resetting the password for this username resolves the problem, but the problem continues to appear at random intervals. What can I do to determine what is causing this strange anomaly and prevent the credential corruption from occurring again?
We are using Windows Server 2008 with IIS 7.