I finally got the site to come up with some advice from the SQL Server team on Microsoft Technical Communities.  I'm still not sure what was going on.  I was advised that recent updates to SQL Server cause problems for migrating databases between servers by taking and restoring from a backup, because SQL Server creates new SID for all the logins.  So when you create the new login on the target site, you have to use a stored procedure to move the SID to it.

The reason I don't think this was the problem is that another tech suggested a new connection string, which I tried, and it worked:

Data Source = .\SQLEXPRESS; Initial Catalog = YourDBName; Integrated
Security=True;

I modified my web.config to use this and the site came up.  Someday I may even figure out why.  But it's working.  Now, on to documenting and testing the upgrade...

Alex,

Thanks for your response, yes I back everything up!

You raise a good question. I'm trying to decide which version to upgrade to.  5.1.1 appears to have many great and wonderful options (which aren't available in the Community edition); and the code base is relatively recent in production.  4.x has a long and stable history, but here comes 5.x, how long will 4.x continue to be a valid platform?  Any feedback on this?

I'm quite concerned about the reported SQL Server 2000 issues, because I have NO WAY to find out if I'll have them on my test system (which is what I just brought up).  My test system (aka my Vista laptop) runs SQL Server 2005 Express (because that's what I could get; I looked for SQL Server 2000 Express and couldn't find it).  Only my production server uses SQL Server 2000, so I won't find the problem until I go into production (a really bad scenario).  When do you expect 5.1.2 to be available?

Due to the long time it took me to get my test site working, I now have only about 3 weeks to upgrade.  Frankly, I'll probably go to 4.9.4 just because it's less likely to give me trouble with the SQL server.  I'll keep an eye out for 4.9.5, thanks for the tip.

Right, I've confirmed with my ISP that I should be able to upgrade my SQL server version to 2005 at no charge.  I'll certainly ask about 2008 but I don' t know if it's available (our hosting contract is on the cheap).  From what you say, if I can get to SQL Server 2005, that should be adequate for 5.2.0.