Oh no, I haven't gotten around to upgrading yet (still waiting for a good window)...I was just asking you, since you just upgraded 3 different sites...Just wondering.  Glad to hear that you haven't had any problems.

Thanks again!

I found it!!!!!!!!!!!!!!!!!!!!!!

Ok, I went through the web.config file line by line.

When I originally set up my install of DNN I remember having problems, so I changed something in there that really no one talks about, but it is obviously used for the encrytion/decryption of the user accounts.

This line in the web.config file:
<add name="AspNetSqlMembershipProvider" type="System.Web.Security.SqlMembershipProvider" connectionStringName="SiteSqlServer" enablePasswordRetrieval="true" enablePasswordReset="true" requiresQuestionAndAnswer="false" minRequiredPasswordLength="7" minRequiredNonalphanumericCharacters="0" requiresUniqueEmail="false" passwordFormat="Encrypted" applicationName="DotNetNuke" description="Stores and retrieves membership data from the local Microsoft SQL Server database"/>

I changed the "applicationName" value to the name of my LIVE server, thinking that would fix the problem that I had in the original install.  That did it.  When I changed that in the web.config file, I can now log in with the existing accounts.

Most people probably didn't change this value, which is why it isn't mentioned, but hopefully my dumb mistake helps someone else :-)

Thanks!