Failure to connect to server

I helped a user connect to his shared drive on the network from his Mac and while it was working fine before, it now isn’t. It says the password is incorrect, but nothing is wrong with his password. He is able to access his shared drive from parallels. I also tried using my username and password to login to his hdrive, but received the same error message.

He says it happened after he tried to save a PDF from an email attachment from Entourage to his shared drive and then all of a sudden a whole bunch of documents that were in the drive randomly opened up so he shut down his computer.

Any ideas on what needs to be done so he can access his shared drive from his Mac?

Some more information--here is the error message that pops up:

“The finder cannot complete the operation because some data in smb://server could not be written (error code –36)”

This second message does not go away when “ok” is clicked:

“Sorry you entered an invalid username or password”

We were able to fix it, but we still don't know why it stopped working.