.net – VB.net dll stops working after SA account disabled

Ok everyone,
Got a wierd one here.

I've written approx 4 projects that utilize a central DLL for database access. The DLL was written in VB.NET using the .NET 3.1 framework.

All the code works great. Recently, I went through all the code and updated the connection strings to use a new username and password since they were using the SA account on SQL Server 2005.

After recompiling and uploading the DLL to the web server, I disabled the SA account.

All of a sudden, the DLL stopped working. It just stopped. I know that the code is ok because I copied it into a aspx file and it worked. So, basically, I'm stumped.

I had to re-enable the SA account in order to get things back to normal, but I really would like to eventually disable it.

Any ideas?

Thanks in advance.
Richard M.