Is the Local Directory field blank, or is is missing altogether in the Server settings window for your mail account? If the field is missing, have you tried grabbing the bottom of the Server Settings window with the mouse, and stretching it open? I had to do that with one version of Mozilla, before I could see the Local Directory field, since it had been compressed to a plain line.
At this point you can wait for someone else to offer more help, or try the following, if nothing I've suggested so far helped:
You could REMOVE the netvision.net mail account, then add it back, using the REMOVE ACCOUNT and ADD ACCOUNT buttons on the Mail & Newsgroups Account Settings window. Then see if you can find the server settings, Local Directory area, and post back.
Another solution might be to create a new profile, using the Netscape Profile Manager, and then copy over the mail files (inbox, sent, drafts, etc) from the old profile to the corresponding location in the new profile, details here:
http://home.att.net/~cherokee67/NS7newprofile.htmlUserAgent: Mozilla/5.0 (Windows; U; Windows NT 5.1; en-US; rv:1.7.8) Gecko/20050511