SQL error

I have been suing CIS for a while. Since updating to free version 4.1.150349.920 I have been having an issue with a locally developed Windows application. It uses a menu system to access our internal database and support the filing of some standard forms. Since the update I get an error message of:

Runtime error ‘-2147467259 (80004005)’:
[DBNETLIB][Connection Open (Connect().] SQL Server does not exist or access denied.

I will also sometimes get an indication that it is SQL(1443) - presumably a port number?

I have tried defining the application as a trusted application, defining a rule for it, and assuring that port is open, but nothing has worked so far. The IT tech who wrote the application can’t find a cause - it works for any and everyone else - and works for me IF I uninstall CIS - merely exiting the program does not allow the application to execute. As the application is used almost daily, it is not a situation I can continue to live with - and as it used to work without a problem before the update, I am wondering if you have any suggestions.

Jeff Rees