This may not be very helpful, but I'm having a similar problem--Prior to this week I could FTP to update my website using a 3rd party program and now I can't. I'm thinking their march 23rd upgrade thingamajig is creating changes in the informaton we need to give the 3rd party program, even though mine (serif WebPlus SE) says it can make a connection to the server when I hit "test connection." My error is 5505: About.com:Access Denied or something like that. What a pain! I'm a writer not a computer whizz! But it seems pretty clear that this was an intentional change related to something they wanted to change and have yet to resolve.