The error message is not coming from WinSCP. So I cannot tell what does it mean.

Hello, I'm using a Linksys wrt610n router with inbuilt FTP and Media Server and an externally connected USB drive to the router. When I call the FTP Server from WinSCP I get a "priv_sock_get_result" error on all user accounts except the automatically created admin account. This worked perfectly before I upgraded the router's f/w so this might be a router issue all together but I take the opportunity of addressing it also to you. My understanding of the error message is that the router is not able to resolve the log-in autentication from the Client. Would you also agree to that interpretation and would it then be a Linksys Linux problem all together? From Linksys I get no valuable answer...Most grateful for any advice...!