Device emulator intermittently unable to connect to sql server 2005 express

I have a VS2008 C# mobile application, that uses COMPACT FRAMEWORK 3.5 database (files), and SQL SERVER 2005 EXPRESS database.  The problem: there is an intermittent problem with connecting to the SQL SERVER 2005 EXPRESS database.  SOMETIMES, I'd get a successful connection, and SOMETIMES I won't.  Nothing changes in-between successive runs, other than testing the updating of my SQLCE files. Why is this?  Because the problem is intermittent, it is very difficult to trace!  I've gotten so desperate, that I've created NEW SQL SERVER instances--whenever the current instance appears to be "hosed-up!!!"  While this may be a temporary fix during testing--it is a bit impractical for PRODUCTION processing!!! Help! ...