Recently I’ve been having a frustrating time using Dreamweaver’s FTP client. For some reason, it kept losing the FTP user name and password whenever I restarted dreamweaver, and it seems I was not alone.
It appears that the problem was caused by a conflict between the version of Dreamweaver I was running and IE7. Downloading the Dreamweaver 8.0.2 updater solved the problem for me. Apparently it can also be cause by a missing registry key, Adobe have a knowledgebase article on the subject.